Diseases & Conditions
This injury affects one of the main ligaments in your knee. It most commonly occurs during sports like soccer, basketball, football and downhill skiing.
Acute respiratory distress syndrome (ARDS) is sudden and serious lung failure that can occur in people who are critically ill or have major injuries.
An abdominal aortic aneurysm can grow slowly and silently. Know the symptoms of this dangerous condition and how it is treated.
This type of seizure produces unexpected symptoms, such as a vacant stare, lip smacking and eyelid fluttering.
Acanthosis nigricans — Comprehensive overview covers causes, treatment of this skin condition.
Learn about diagnosis and treatment options for achalasia at Mayo Clinic.
Achilles tendinitis — Comprehensive overview covers symptoms, causes, treatment of this overuse injury.
An Achilles tendon rupture is an injury that is usually painful and likely to affect your ability to walk. Surgical repair is sometimes necessary.
Learn more about this common skin condition, including causes, acne treatments and simple skin care steps you can do at home to help control it.
Acoustic neuroma is a tumor that grows on the balance and hearing nerve in the head that may cause hearing loss.
An excess of growth hormone causes the bones to keep growing, which can lead to a number of serious complications if left untreated.
Find out more about this skin condition that causes a rough, scaly patch after years of ultraviolet exposure from sunshine or indoor tanning.
Acute coronary syndrome refers to many conditions that cause sudden, low blood flow to the heart. Know the symptoms, causes and treatment.
Learn what happens when the kidneys suddenly stop working, as well as what causes this condition and how it's treated.
Acute liver failure is a rapid loss of liver function, often in someone without liver problems. It's a medical emergency that requires urgent care.
Learn about this cancer that forms in the blood and bone marrow. Treatments include medications and bone marrow transplant.
Learn about this cancer that forms in the bone and bone marrow. Treatments include medications and bone marrow transplant.
Learn the latest treatment and prevention strategies for dealing with the stuffy nose and head pain that can come with this upper respiratory condition.
Learn about this rare but serious disorder of the adrenal glands that's treated by replacing needed hormones.
Displaced endometrial tissue from adenomyosis can cause an enlarged uterus and painful, heavy periods.
Adjustment disorders are stress-related conditions where you feel overwhelmed and have a hard time adjusting to a stressful event or change.
Learn about this rare cancer that begins in the adrenal glands. Find out about symptoms, diagnosis and treatment, including adrenalectomy.
Find out about diagnosis and treatment of adrenoleukodystrophy — a hereditary disorder that affects the brain, nervous system and adrenal gland.
Adult Still's disease — Comprehensive overview covers symptoms, complications, treatment of this inflammatory disorder.
This mental health disorder includes a combination of persistent problems, such as difficulty paying attention, hyperactivity and impulsive behavior.
Learn more about the harmless dark spots on your skin that tend to appear as you age, especially in areas exposed to the sun. Treatment is available.
Agoraphobia is an anxiety disorder in which you fear and avoid places or situations where you might feel panicked, trapped, helpless or embarrassed.
That fullness in your ear when on an airplane that's climbing or descending results from uneven air pressure between your middle ear and the environment.
In this group of inherited disorders, there is little or no production of melanin, a pigment that determines hair, skin and eye color and vision development.
Having an immediate reaction after drinking alcohol, such as a stuffy nose and skin flushing, might indicate alcohol intolerance.
Alcohol poisoning is a serious and sometimes deadly consequence of drinking large amounts of alcohol in a short time. Here's what to do in an emergency.
Unhealthy alcohol use ranges from mild to severe, including alcoholism and binge drinking, putting health and safety at risk. Early treatment is important.
Drinking heavily over years can cause inflammation of the liver. If you have alcoholic hepatitis, you must stop drinking.
Allergy symptoms can range from mild to severe, even life-threatening. Most allergies can't be cured, but treatments can help.
An allergic reaction to meat-based meals had researchers stumped — until they connected the condition to bites from certain ticks.
Alzheimer's disease causes a progressive loss of brain cells that leads to memory loss and the decline of other thinking skills.
Learn about causes and treatment of ambiguous genitalia, a rare disorder of sex development in which a baby's external genitals are not clearly male or female.
Learn more about the symptoms and treatment of this rare, noncancerous (benign) tumor.
Absence of menstruation (amenorrhea) may be linked to an underlying, treatable problem. Learn about amenorrhea causes and when you should see a doctor.
Read about the causes of memory loss, and steps you can take to get it back.
A rare, serious condition occurs when fetal cells or the fluid that surrounds a baby in the uterus during pregnancy enter the mother's bloodstream.
This rare disease can affect different organs in different people. Find out how early and accurate diagnosis can lead to better outcomes.
This progressive nervous system disease, also known as Lou Gehrig's disease, destroys nerve cells.
Learn about this cancer that affects the anal canal and causes bleeding and pain. Treatment is usually with a combination of radiation and chemotherapy.
Learn what causes a tear in the anus and how to prevent or treat this often painful condition.
Learn about the causes, treatment and self-care tips for this common, sometimes embarrassing condition.
Anaphylaxis, a severe allergic reaction, is an emergency. Learn who's at risk, what to watch for and what to do when it occurs.
There are many forms of anemia, in which you lack enough healthy red blood cells to carry oxygen throughout your body. They can cause fatigue and weakness.
Angelman syndrome – Find out more about symptoms, causes and treatment of this rare neurological and developmental disorder.
Learn about a certain type of chest pain caused by reduced blood flow to the heart. This symptom indicates underlying heart disease.
Learn about this rare cancer that begins in your blood vessels and lymph vessels. Treatments include surgery, radiation therapy and chemotherapy.
Anhidrosis — Comprehensive overview covers symptoms, causes, treatment of this inability to sweat normally.
Ankylosing spondylitis is an inflammatory disease that, over time, can cause some of the vertebrae in your spine to fuse. This condition can be disabling.
Anorexia is an eating disorder characterized by an abnormally low body weight, intense fear of gaining weight and a distorted perception of body weight.
Anorgasmia is regular difficulty reaching orgasm after plenty of sexual stimulation. It affects many women, causing distress.
Anterior prolapse happens when tissues supporting pelvic organs weaken and stretch, bulging into the top front part of your vagina. Learn how it's treated.
Anthrax — Comprehensive overview covers symptoms, vaccine, risks of this rare but deadly bacterial disease.
Learn more about why you might get diarrhea while taking antibiotics, as well as how to treat or prevent this uncomfortable and sometimes serious problem.
Antiphospholipid syndrome — Learn about causes and treatment of this blood disorder that mainly affects women and may cause blood clots and miscarriages.
Antisocial personality disorder — Learn about symptoms, causes, diagnosis and treatment of this mental health disorder.
Learn the symptoms of this mental health condition, and ways to manage worry and fear that interfere with your daily activities.
Aortic dissection occurs when blood leaks through a tear in the inner layer of the aorta. Left untreated, the condition can be fatal.
Learn more about diseases that affect the heart valve between the main pumping chamber of your heart and the main artery to your body.
Learn more about the symptoms and treatment of this condition in which the heart's aortic valve doesn't close tightly.
Learn more about the symptoms and treatment of this heart condition that occurs when the heart's aortic valve narrows.
Aphasia — Comprehensive overview covers causes, treatment, coping skills for this communication disorder.
Aplastic anemia occurs when your bone marrow stops producing enough new blood cells. It's a serious problem, but treatments are available.
Is it just a bellyache or something more serious? Find out about the signs, symptoms and treatment for appendicitis — an inflammation of the appendix.
Learn about the symptoms, causes and treatment for hardening of the arteries.
Abnormal connections between arteries and veins may cause certain complications. Learn more about the causes and possible treatment options.
An AVM is a tangle of blood vessels that affects the flow of blood and oxygen, but treatment can help.
Learn about how different types of arthritis affect joints in different ways, along with how to get relief from arthritis pain.
Asbestosis is a lung disease caused by exposure to asbestos fibers. Symptoms such as shortness of breath and coughing may not appear until decades later.
Learn more about the causes, treatment and prevention of this roundworm infection.
This fungal lung infection is caused by inhaling certain mold spores. It may be serious in those with asthma or other chronic lung disease.
Asthma — Comprehensive overview covers symptoms, treatment of this chronic lung condition.
Many people have astigmatism, an irregular curvature of the eye's surface that can cause blurred vision. Treatments are corrective lenses or laser surgery.
Learn about this type of cancer that can occur in the brain or spinal cord.
Ataxia — Comprehensive overview covers causes and treatments for this lack of muscle coordination.
Atelectasis is a partly or completely collapsed lung. Know the symptoms and causes.
Learn about causes, symptoms, treatments and self-care tips for this common fungal infection.
Learn more about the causes, symptoms and treatments of this itchy rash that most often begins before age 5 and persists.
Find out about atrial fibrillation, a heart condition that causes your heart to beat rapidly. Know the symptoms and risk factors and how to get treated.
Learn more about this abnormal opening between the heart's upper pumping chambers. It's a common problem at birth, but can be readily treated.
Atrial tachycardia is a type of supraventricular tachycardia. Learn about innovative treatment of this heart arrhythmia at Mayo Clinic.
Atrioventricular canal defect: Holes in the heart and defective valves interfere with normal heart function.
Atrioventricular nodal reentry tachycardia (AVNRT) is the most common type of supraventricular tachycardia. Learn about innovative treatment of this heart arrhythmia at Mayo Clinic.
This condition affects children, and may continue into adulthood. It can include difficulty sustaining attention, hyperactivity and impulsive behavior.
With this depression, you may brighten in response to positive events, eat and sleep too much, feel heaviness in your arms or legs, and feel rejected.
Atypical hyperplasia — Comprehensive overview covers treatment of atypical ductal hyperplasia and atypical lobular hyperplasia.
Autism spectrum disorder is a serious condition related to brain development that impairs the ability to communicate and interact with others.
This type of hepatitis occurs when your immune system attacks your liver with destructive antibodies. Immune-suppressing medication is the main treatment.
Autoimmune pancreatitis is a newly discovered disease of the pancreas that may be mistaken for pancreatic cancer.
Damage to the nerves that control involuntary body functions, such as blood pressure and digestion, results in autonomic neuropathy.
A broken bone or dislocated joint can interrupt blood flow to the bone, causing avascular necrosis (osteonecrosis), the death of bone tissue.
Baby acne — Comprehensive overview covers causes, symptoms, treatment of this newborn complexion problem.
Back pain is one of the most common reasons people go to the doctor. Home treatment and proper body mechanics often will heal your back within a few weeks.
Learn about symptoms, treatments and prevention of this common vaginal infection.
Bad breath — Comprehensive overview covers causes, treatment and prevention.
Learn about causes, treatments and home remedies — including cool compresses and not smoking — for bags under eyes, which become more common as you age.
Baker's cyst — Comprehensive overview covers symptoms, causes, treatment of this bulge behind the knee.
Learn about the causes and treatment of conditions that leave you feeling dizzy or unsteady.
Barrett's esophagus, which is linked to chronic heartburn, can turn into cancer of the esophagus. Learn about treatment.
A Bartholin's cyst is a fluid-filled lump near the vaginal opening. It's rarely serious, but when infected, it can be painful.
Learn about symptoms, treatment and prevention of this common skin cancer that often occurs on the head and neck.
Bed-wetting — Learn about causes and treatments, including moisture alarms, bladder training and medications.
See pictures and learn more about the symptoms, treatment, prevention of these parasitic insects and their bites.
Learn about the symptoms, treatment and prevention of this common skin condition that often affects older adults with limited mobility.
Learn more about symptoms, treatment, self-care tips and prevention of bee stings, which in some people cause severe allergic reaction.
This rare disorder causes blood vessel inflammation throughout the body. Signs and symptoms depend on which parts of the body are affected.
Bell's palsy causes temporary facial paralysis. Find out more about why it happens and what to do about Bell's palsy.
Benign paroxysmal positional vertigo — Comprehensive overview covers symptoms, causes, treatment of intense dizziness episodes.
Benign prostatic hyperplasia — also known as an enlarged prostate — is a common, but treatable urinary condition in older men.
Learn more about this congenital condition in which the heart's aortic valve has two cusps instead of three, which can cause the aortic valve to narrow.
This digestive problem tends to develop in people who have had stomach surgery. It sometimes contributes to gastroesophageal reflux disease (GERD).
People with binge-eating disorder frequently consume unusually large amounts of food and feel unable to stop eating. Learn about symptoms and treatment.
Bipolar disorder causes extreme mood swings that include emotional highs (mania or hypomania) and lows (depression).
Do you still need to worry about the bird flu? Get the facts about symptoms, causes and prevention of this infectious disease.
Black hairy tongue is a temporary, harmless oral condition that gives your tongue a dark, furry appearance.
Blood in the urine (hematuria) sometimes is a sign of bladder cancer. Learn about other bladder cancer signs and symptoms and explore treatment options.
Bladder exstrophy, also known as bladder exstrophy-epispadias complex, or BEEC, is a rare birth defect that can be repaired surgically.
Minerals in your urine can crystallize if you have trouble emptying your bladder completely, creating this potentially painful condition.
This microscopic organism found in the stools of some people usually resolves on its own. Whether it causes digestive problems isn't clear.
Blepharitis — Comprehensive overview covers symptoms, treatment and self-care for this eyelid condition.
Blind loop syndrome — Comprehensive overview covers symptoms, causes, treatment of this bowel disorder.
A blocked tear duct is common in newborns, but older children and adults can be affected, too. Find out what causes this eye disorder and how it's treated.
Seeing blood in your urine can be alarming. Although the cause might be benign, it's important to see a doctor in case the cause is more serious.
Body dysmorphic disorder — Learn about symptoms, causes and treatment of this mental disorder, which includes preoccupation with appearance.
Body lice are tiny insects that live in your clothing and feed on your blood. Find out how to treat and prevent this itchy nuisance of a bug.
Learn about symptoms, causes, treatment and prevention of these painful pus-filled infections that cause bumps under your skin or leaking sores.
Bone cancer most commonly affects the long bones in the arms and legs. Some varieties occur primarily in children, while others affect mostly adults.
Bone metastasis — Comprehensive overview covers symptoms and treatment of bone metastasis in people with cancer.
Joint damage due to osteoarthritis is the most common cause of bone spurs. Most bone spurs create no problems and don't need treatment.
This mental health disorder includes a pattern of unstable intense relationships, distorted self-image, extreme emotions and impulsiveness.
This rare but serious condition can be caused by bacteria that have contaminated food or an injury. Learn more about how to prevent it.
Severe brachial plexus nerve injuries usually result from auto or motorcycle accidents. Repairing or replacing the nerves can help restore arm function.
Find out more about the symptoms, diagnosis and treatment of a slow heartbeat.
Brain AVM (arteriovenous malformation) — Comprehensive overview covers causes, symptoms and treatments.
Learn about detection, diagnosis, treatment options and advances for brain aneurysm, including surgical clipping, endovascular coiling and flow diverters.
Learn about symptoms, diagnosis and treatment of cancers that spread to the brain (secondary, or metastatic, brain tumors).
Find out more about the different brain tumor types and treatments, including surgery, radiation therapy and chemotherapy.
Learn about this common cancer, including information on prevention, symptoms, diagnosis and treatment.
A firm, round lump in breast tissue could be a fluid-filled cyst. Typically not cancerous, breast cysts often need no treatment.
Learn about possible causes and treatments for breast pain, along with self-care remedies that may help keep you comfortable when breast pain flares.
A severely broken ankle may require surgery to implant plates, rods or screws into the broken bone to maintain proper position during healing.
Treatment depends on the site and severity of the injury. Simple breaks might be treated with a sling and ice. Complicated fractures may require surgery.
Broken collarbone — Comprehensive overview covers causes, symptoms and treatment of this common injury.
A severely broken foot may require surgery to implant plates, rods or screws into the broken bone to maintain proper position during healing.
You may be at higher risk of a broken hand if you participate in contact sports like football or hockey, or if you have a condition in which bones become thinner and more fragile (osteoporosis).
Find out more about this temporary heart muscle condition that can be triggered by stressful events.
Broken leg — Comprehensive overview covers symptoms, diagnosis and treatment of this type of fracture.
Broken nose — Comprehensive overview covers symptoms, causes and treatments of a nasal fracture.
Broken ribs — Comprehensive overview covers symptoms, causes and treatment of rib bone fractures.
Pain when wearing shoes and difficulty walking can signal a broken toe — so see your doctor to help it heal and ease pain.
The most common type of wrist fracture occurs when people try to catch themselves during a fall and land hard on an outstretched hand.
Bronchiolitis is a common lung infection in young children and infants. Winter months are the peak time for this infection.
Bronchitis is an inflammation of the tubes that carry air to and from the lungs. Coughing and shortness of breath are the major symptoms.
Contact with raw dairy products is the most common cause of this serious infectious disease that spreads from animals to people.
Learn about the symptoms, causes and treatments for this heart rhythm disorder that is sometimes inherited.
Bruxism is a condition in which you grind, gnash or clench your teeth unconsciously when you're awake or while you're sleeping.
Read about this blood vessel disease that limits blood flow, especially to your hands and feet. Quitting smoking is the best treatment for this condition.
With bulimia, a serious eating disorder, you eat large amounts of food and then purge to get rid of extra calories. Learn about symptoms and treatment.
Learn about the symptoms, treatment and self-care strategies for this blistery skin condition that affects older adults.
A delay or obstruction in the pathway that electrical impulses travel to make your heart beat can make it harder for your heart to pump blood.
A bunion is a bony bump that forms on the joint at the base of your big toe. Learn more about the causes and treatments of this sometimes painful disorder.
This chronic burning, without an obvious cause, may affect the tongue, gums, lips, cheeks, roof of your mouth or widespread areas of your mouth.
Understand how to prevent, treat and recover from burns ranging from minor to life-threatening.
Bursitis is the painful inflammation of small, fluid-filled sacs that cushion the bones, tendons and muscles near your joints. Ice can ease symptoms.
Learn more about this infectious disease that is becoming more common and often affects older adults in a health care facility, often after antibiotic use.
Chronic obstructive pulmonary disease (COPD) — Comprehensive overview covers symptoms, treatment of this lung disease.
Find out the basics about cancer, including symptoms, causes and treatments. Learn steps you can take to prevent cancer.
Canker sore — Learn about the causes, treatment and prevention of this painful mouth sore.
Carbon monoxide is colorless, odorless, tasteless — and extremely dangerous. Don't count on detecting it. Instead, prevent it.
Find out about skin flushing and other symptoms of this syndrome caused by a rare cancer called a carcinoid tumor.
Learn about these slow-growing cancers that usually begin in the digestive system or in the lungs. Treatments include peptide receptor radionuclide therapy.
In this uncommon and aggressive type of cancer, doctors aren't sure where the cancer began. Learn how they determine which treatments are most likely to help.
Most often the result of a severe heart attack, cardiogenic shock is rare but can be fatal if not treated immediately.
Cardiomyopathy is a disease of the heart muscle that makes it harder for your heart to pump blood to the rest of your body.
Learn about carotid artery disease symptoms, prevention and treatment options including stenting, angioplasty and carotid endarterectomy.
Carpal tunnel syndrome—Learn more about the symptoms, diagnosis and treatment of this common nerve disorder affecting the hand and arm.
This rare disorder involves an overgrowth of cells in your body's lymph nodes. Treatment varies depending on how many lymph nodes are involved.
Cataracts often affect people as they age, causing blurry, dim vision that gets worse over time. Learn how surgery to replace the cloudy lens can help.
Find out about diagnosis and treatment options, including surgery, for these abnormal blood vessel formations of the brain and spinal column.
Cavities, also called tooth decay, are permanently damaged areas in the hard surface of your teeth that develop into tiny openings or holes.
In celiac disease, wheat protein (gluten) in food damages the small intestine, making it hard to absorb nutrients and causing a variety of symptoms.
Cellulite — Comprehensive overview covers causes and treatments of this common skin condition.
Find out more about this potentially serious skin infection and how a few simple skin care tips can help prevent it.
Find out how a mix-up in brain signals can affect your breathing during sleep, plus how this breathing disorder can be treated.
Damage to the developing brain, usually before birth, causes this disorder of movement, muscle tone or posture.
Screening with Pap tests can reduce the risk of this cancer that begins in the cervix. Learn more about symptoms, causes, prevention and treatment.
This rare movement disorder causes neck muscles to contract involuntarily. This can make your head twist or turn into often painful positions.
As people age, the spinal disks in the neck shrink and bone spurs often develop. If symptoms occur, nonsurgical treatments are usually effective.
Sexually transmitted infections are often the reason why a woman develops inflammation of the cervix, which can cause abnormal discharge and bleeding.
Learn more about this inflammatory, infectious disease caused by the parasite Trypanosoma cruzi, which is found in the feces of the triatomine (reduviid) bug.
Learn how to spot the symptoms and how doctors treat this group of peripheral nerve disorders.
Learn about the memory and thinking changes that sometimes happen during and after cancer treatment. Find out about chemo brain treatments and ways to cope.
Chest pain has many possible causes — and some of them are serious. Here's why it's so important to see your doctor about chest pain.
Find out about the symptoms, causes, and treatment of this brain disorder in which brain tissue extends into your spinal canal.
Learn more about the symptoms, treatment and prevention of this once common childhood illness.
For some people, cold exposure means chilblains — itchy, red patches that can become sores. Find out how to treat and prevent this seasonal skin condition.
Child abuse includes physical, sexual, emotional and medical abuse, as well as neglect. Learn about signs, risk factors, how to get help, and prevention.
Speech therapy can help children with this speech disorder that's caused by a problem with communication between the brain and the muscles used for speech.
The lungs and airways of children with asthma become inflamed, interfering with daily activities. Some children can have dangerous attacks.
Childhood obesity can lead to various conditions, including type 2 diabetes and high blood pressure. Learn how to protect your child's health.
Childhood schizophrenia is a severe brain disorder that results in hallucinations, delusions, and disordered thinking and behavior.
Chlamydia trachomatis is a common sexually transmitted infection (STI) that can lead to serious health problems if left untreated. Learn more about symptoms, treatment, prevention.
Learn about symptoms, risk factors, diagnosis and treatment, including transplant, for this rare cancer that affects the bile duct of older adults.
Cholecystitis is gallbladder inflammation. Learn the causes, symptoms, complications and treatment.
Cholera is a treatable, yet potentially fatal bacterial disease that causes diarrhea and dehydration. Learn how to lower your risk.
Cholestasis of pregnancy makes an expectant mom very itchy, and it can be dangerous for her baby. Know the causes and treatment.
Chondrosarcoma is a rare type of cancer that primarily affects bone, particularly in the pelvis, hips and base of the skull. Surgery is the main treatment.
Chordoma is a rare type of bone cancer that occurs in the spine. Chordoma treatments include proton beam radiation therapy and surgery.
This rare type of cancerous brain tumor occurs mainly in children under 2. Treatment usually involves surgery and radiation therapy.
A cough that lasts for weeks could be caused by smoking, postnasal drip, asthma, acid reflux, respiratory infections, COPD or another underlying problem.
If you have a headache most days, you might have one of the most disabling headache conditions, chronic daily headaches. Aggressive treatment and long-term management might help.
This exercise-induced muscle and nerve condition causes pain, swelling and sometimes disability in the affected muscles of the legs or arms.
This complicated disorder may be triggered by an infection. While there's no cure for chronic fatigue syndrome, treatment focuses on symptom relief.
Chronic granulomatous disease is usually diagnosed in childhood. The condition makes it difficult for your body to fight infections.
Learn how this long-lasting skin condition that causes itchy welts is diagnosed and what treatments work best.
Learn about kidney failure symptoms, tests, diagnosis and treatment options, including medication, dialysis and kidney transplant.
Learn about this cancer that forms in white blood cells called lymphocytes. Treatments include chemotherapy, targeted therapy and immunotherapy.
Learn about chronic myelogenous leukemia (CML) symptoms and causes. Find out how doctors treat CML, including targeted therapy and bone marrow transplant.
Chronic pelvic pain can be a symptom of another disease or a condition in its own right. Learn how this painful condition is diagnosed and treated.
Read more about possible causes of lasting sinus troubles, what treatments are available and how you can prevent this problem in the future.
This type of brain degeneration is likely caused by recurrent concussions, but what causes the damage isn't well understood.
Churg-Strauss syndrome – Learn how this rare blood vessel disease may cause breathing trouble, face pain and a persistent runny nose. Medications can help.
Cirrhosis is an advanced stage of scarring and damage of the liver. Find out about symptoms and treatment of this life-threatening liver condition.
Too little blood flow to your legs and arms can cause pain, especially during exercise. Learn more about diagnosing and treating this condition.
Surgery can fix openings or splits in the upper lip, or the roof of the mouth (palate), or both types of these birth defects.
This term describes a range of congenital foot abnormalities in which the foot is twisted out of shape or position, keeping it from moving up and down.
These painful headaches cause severe pain on one side of the head and tend to occur in frequent bouts called cluster periods.
Learn more about the causes and treatment of this usually congenital heart condition that is treatable but requires lifelong follow-up.
Cold sore — Comprehensive overview covers symptoms, causes, treatment, prevention of this common lip sore.
Learn more about the symptoms and treatment of this allergic skin reaction caused by cold that most often affects young adults.
Consoling a baby who cries a lot for no apparent reason is a challenge. Learn strategies for caring for your infant and coping with the stress.
Find out about symptoms and risk factors for colon cancer, also called colorectal cancer. Learn about treatment options, including minimally invasive surgery.
Have you had your colonoscopy? Colon polyps typically don't cause symptoms, so it's important to have regular screenings.
Coma is a state of prolonged unconsciousness with many possible causes. While it rarely lasts longer than a few weeks, some people never wake from a coma.
Learn more about how to prevent and treat this common respiratory infection.
Learn more about when to see the doctor and how to treat this viral infection that causes a runny nose and nasal congestion in babies.
Find out tips for preventing and dealing with this common skin condition that causes small, rough growths on your fingers and hands.
This neurological condition often strikes an arm or leg after an injury or surgery. The sooner treatment starts, the better the chance for remission.
In complicated grief, painful emotions of loss don't improve with time and are so severe that you have trouble recovering and resuming your own life.
Compulsive gambling is an addictive disorder — the uncontrollable urge to keep gambling despite the toll it takes on your life.
Compulsive sexual behavior or hypersexuality is an excessive preoccupation with sexual fantasies, urges or behaviors that disrupts your life or is harmful to you or others.
Concussion — Comprehensive overview covers symptoms, causes and treatment of this common brain injury.
Congenital adrenal hyperplasia (CAH) is a group of inherited genetic conditions that limit your adrenal glands' ability to make certain vital hormones.
Learn about symptoms, tests and treatments for a problem in the structure of the heart (congenital heart defect) that is present in a child at birth.
Learn about treatments and complications of heart defects present at birth and care for adults with these defects.
Learn about these mitral valve defects present at birth that can cause a narrowed or leaky valve.
Congenital myopathies — learn about these rare muscle diseases associated with lack of muscle tone and weakness as well as skeletal problems.
If an early embryo only partially separates and two fetuses develop, they remain physically connected — most often at the chest, abdomen or pelvis.
Chronically constipated? Find out what could be the cause and learn how to prevent and treat infrequent bowel movements.
Learn what could cause constipation in your child, what you can do to prevent it and treatments that will get the bowel moving again.
Contact with certain substances, such as poison ivy, skin lotions and detergents, can cause a red, itchy rash. Here's how to manage this common form of dermatitis.
Convergence insufficiency typically causes one eye to drift outward when you’re trying to focus, making it hard to concentrate and tiring your eyes.
Find out more about these hardened areas of skin that often affect the feet and fingers. Try these self-care tips to make corns and calluses disappear.
Learn about this serious heart condition in which the major blood vessels that supply your heart with blood become damaged or diseased.
Costochondritis — Comprehensive overview covers causes, treatment of this usually harmless chest wall pain.
Cough headaches — Comprehensive overview covers causes, symptoms and treatments of this unusual headache type.
Learn about the symptoms, treatments and home care tips for this short-lived type of seborrheic dermatitis that's common in infants.
Learn more about this noncancerous tumor that forms near the brain's pituitary gland, including diagnosis and treatment options.
Craniosynostosis is the premature fusing of joints between the bone plates of an infant's skull before the brain is fully formed.
Learn more about the definition, symptoms, causes and diagnosis of this degenerative brain disorder that leads to dementia.
Crohn's disease — Comprehensive overview covers symptoms, complications, treatment of this inflammatory bowel disease.
This upper airway infection obstructs breathing and causes a barking cough. It involves swelling around the voice box, windpipe and bronchial tubes.
Cryptosporidium infection is caused by small parasites that infect the intestines, causing diarrhea that can become life-threatening if you have a weak immune system.
Cushing syndrome is caused by high levels of the hormone cortisol in your body. Learn about symptoms, causes and treatment for this endocrine disorder.
Primary cutaneous B-cell lymphoma is a type of immune system cancer that affects the skin. Cutaneous B-cell lymphoma treatment usually involves surgery.
Learn about this type of non-Hodgkin's lymphoma that attacks the skin. Find out about cutaneous T-cell lymphoma (CTCL) symptoms, diagnosis and treatments.
Cyclic vomiting syndrome often starts in childhood and is marked by spells of vomiting several times an hour over a period of hours or days.
Learn more about the symptoms, causes, treatment of this foodborne intestinal illness that causes watery, sometimes explosive, diarrhea.
Also called cyclothymic disorder, this mood disorder causes emotional ups and downs that are less extreme than bipolar disorder. Learn about treatment.
Cystic fibrosis — Learn about the causes, symptoms and treatment of this inherited condition that causes severe damage to the lungs and digestive system.
Cystitis is an inflammation of the urinary bladder. It's most often caused by a bacterial infection but may have other causes.
Understand the symptoms, diagnosis and treatment of this common viral infection that can cause health problems in babies.
Learn about the causes of this sometimes embarrassing, flaky scalp disorder and which medicated shampoos and self-care habits may help control it.
De Quervain's tenosynovitis — Comprehensive overview of symptoms, treatment of this painful wrist condition.
You can develop deep vein thrombosis, a potentially serious condition, with no symptoms. It's good to know the risk factors.
Dehydration is especially common and dangerous for infants, young children and older adults. Learn more about treating and preventing dehydration.
Understand what causes delayed or absent ejaculation and the possible treatments.
Learn more about this sleep condition that causes a delay in usual sleep patterns.
This serious disturbance in mental abilities develops fast and results in confused thinking and reduced awareness of surroundings. Symptoms and causes vary.
Dementia is a group of symptoms with many causes. The symptoms affect daily life, but some of them may be reversible.
Find out how to prevent and treat dengue fever, a serious, mosquito-borne infection most common in tropical parts of the world.
Depersonalization-derealization disorder is when you feel that you're observing yourself from outside your body or that things around you aren't real.
Depression is a mood disorder that causes a persistent feeling of sadness and loss of interest and can interfere with your daily functioning.
Learn about the types, symptoms, causes, role of moisturizing in treating this common itchy skin condition that affects infants, children and adults.
Dermatofibrosarcoma protuberans (DFSP) — Overview covers diagnosis and treatment. DFSP treatments include Mohs surgery, radiation and targeted therapy.
Dermatographia — Comprehensive overview covers symptoms, treatment of this skin condition.
Muscle weakness and a skin rash are hallmarks of dermatomyositis. There's no cure, but treatments can relieve symptoms.
Learn how uneven nostrils can cause congestion, nosebleeds or other symptoms in severe cases.
DiGeorge syndrome (22q11.2 deletion syndrome) is a disorder caused by a defect in chromosome 22, resulting in poor development of several body systems.
Learn more about the different types of this blood sugar disorder, who's at risk and how each can be treated.
Learn more about this unusual disorder that disrupts the body's fluid balance, causing excessive urination and possibly leading to dehydration.
Diabetic coma is a life-threatening diabetes complication. Learn about its causes, treatment and prevention.
Learn more about the symptoms, treatment and prevention of this life-threatening diabetes complication caused by extremely high blood sugar levels.
Learn more about the causes, symptoms and treatment of low blood sugar for people with diabetes.
Learn more about the symptoms, treatment and prevention of this serious diabetes complication.
Diabetic nephropathy is a common kidney disease in people with diabetes. Learn how treating your diabetes may help prevent serious damage to your kidneys.
Diabetic neuropathy is nerve damage due to uncontrolled high blood sugar. Know the signs and how to take steps to prevent this diabetes complication.
Good diabetes control and regular exams can help prevent this diabetes complication that affects the eyes. Find out how.
Dealing with diaper rash? Follow these tips to soothe your baby's irritated skin.
Learn more about what causes this common, unpleasant digestive condition, and how you can treat and prevent it.
Bony hardening of ligaments where they attach to your spine might cause no symptoms, or it can cause progressive pain and stiffness.
Learn more about the causes and treatment of this heart disorder in which the main pumping chamber of the heart stretches and can't pump blood well.
Diphtheria is a serious bacterial infection that can cause organ damage and breathing problems. This disease is often treatable, but also preventable with a vaccine.
Dislocated elbow — Comprehensive overview covers symptoms, causes, treatments of this common elbow injury.
Dislocated shoulder — Comprehensive overview covers symptoms, causes and treatment of this shoulder injury.
Dislocation — Comprehensive overview covers causes, treatment of this painful injury. Dislocation occurs most frequently in shoulders and fingers.
Dissociative disorders are mental disorders that involve experiencing a disconnection between thoughts, memories, surroundings, actions and identity.
This common colon disease develops when small pouches form in the colon wall and become infected, causing pain, fever and abnormal bowel function.
Dizziness has many possible causes. How long it lasts and any other symptoms you have can help pinpoint the cause.
Learn about symptoms, diagnosis and treatment of this uncommon abnormality of the uterus that's present at birth.
In this condition, two blood vessels in the heart connect to the heart's right ventricle, instead of one to the right and one to the left ventricle.
Down syndrome is a genetic disorder caused when abnormal cell division results in extra genetic material from chromosome 21.
Learn about the symptoms and treatment of inflammation of the sac surrounding the heart in post-cardiac injury syndromes.
With drug addiction (substance use disorder), you can't control your use of legal or illegal drugs or alcohol and may continue using despite the harm it causes.
Learn which drugs are more likely to cause an allergic reaction, what symptoms look like and what treatments can calm such a reaction.
Dry eyes is a common — and very treatable — condition. Find out what causes dry eyes and how to relieve symptoms.
Blurred or reduced central vision could be a sign of macular degeneration. Find out about symptoms and treatment for this common eye disorder.
Dry mouth (xerostomia) refers to a condition in which the salivary glands in your mouth don't make enough saliva to keep your mouth wet.
Dry skin — Comprehensive overview covers causes, risk factors, treatment and prevention. Learn skin care tips that help keep your skin moist and healthy.
Dry socket, a painful dental condition, occurs when the blood clot at the site of a tooth extraction dislodges or dissolves before the wound has healed.
Noninvasive breast cancer often has no signs or symptoms. Find out how doctors diagnose DCIS and learn about treatment, including mastectomy and lumpectomy.
People who have had stomach or weight-loss surgery may suffer from dumping syndrome, which causes cramping, diarrhea and, sometimes, low blood sugar.
Dupuytren's contracture — Comprehensive overview covers symptoms, risk factors, treatment of this hand condition.
Abnormal connections between an artery and the brain's dura; DAF treatments include endovascular embolization and stereotactic radiosurgery.
Dust mite allergy can lead to year-round sniffles and sneezes. Here’s how to find relief.
Very short stature of 4 feet 10 inches or less that results from a genetic or medical condition is considered dwarfism. Learn about causes and treatment.
Dysarthria is a condition that affects muscles used for speaking. Speech therapy and treating the underlying cause may improve speech.
Learn about the symptoms, causes and treatment of this skin condition that causes little blisters on the hands.
Dyslexia is a learning disorder involving difficulty reading due to problems identifying speech sounds and learning how they relate to letters and words.
Learn more about what causes persistent trouble swallowing, along with the ways this problem can be treated.
Find out more about this painful muscle contraction disorder and ways to improve muscle function.
Most strains of E. coli bacteria are harmless, but some can cause severe symptoms. Learn about symptoms and treatment of this common foodborne illness.
These usually get better on their own, but sometimes medicine is needed. Find out more about how doctors diagnose and treat this common ear condition.
Learn simple steps for treatment and self-care of this common problem, including earwax removal.
Eating disorders, such as anorexia, bulimia and binge-eating disorder, seriously impact health. Learn about symptoms and treatments.
Understand the causes and symptoms of these tropical viruses, and tips to prevent illness.
Ebstein anomaly: Comprehensive overview covers symptoms, diagnosis, treatment of this rare heart defect.
Ectopic pregnancy occurs outside the uterus, threatening the mother's life. It can't continue normally. But swift treatment can prevent deadly blood loss.
Ectropion is an eye condition in which your eyelid sags or turns outward. Find out about causes and treatment for this common eye problem.
Learn about the symptoms, causes and treatment of edema — swelling caused by an excess of fluid in body tissues — as well as things you can do at home.
Egg allergy — Comprehensive overview covers symptoms, treatment of this condition.
Learn about these complex genetic disorders that cause problems with connective tissue in the skin, joints and blood vessel walls.
Ehrlichiosis — Comprehensive overview covers symptoms, treatment, prevention of this tick-borne disease.
There's no cure for this serious complication of a heart defect, but treatments can help control symptoms and improve quality of life.
If your blood pressure is slightly elevated, eating better and moving more can help keep it from becoming high blood pressure.
Embryonal tumors include medulloblastomas, embryonal tumors with multilayered rosettes, medulloepitheliomas, atypical teratoid/rhabdoid tumors, and PNETs.
Emphysema is a lung problem that makes it hard to catch your breath. It's one of the conditions that make up chronic obstructive pulmonary disease (COPD).
Encephalitis — Find out more about symptoms, causes and treatment of this potentially life-threatening condition associated with inflammation of the brain.
Encopresis, also called fecal incontinence or soiling, occurs when constipation causes impacted stool to fill the colon, and liquid stool leaks out.
Learn about end-stage renal disease (ESRD), kidney failure symptoms, kidney disease stages and treatments including kidney dialysis and kidney transplant.
Learn about the causes and treatments for this infection of the inner lining of the heart chambers and valves (endocardium) and find out how to prevent it.
Endometrial cancer — Learn about the signs and symptoms, diagnosis, and treatment of this uterine cancer that occurs most often in women after menopause.
Learn about endometriosis, including possible treatments for this condition that causes pain and sometimes infertility.
Gynecomastia is swelling of the breast tissue in boys or men, caused by an imbalance of the hormones estrogen and testosterone.
Learn more about the symptoms, diagnosis and treatment for this heart muscle condition in which the heart is enlarged.
Having a larger than normal liver is a sign of a serious problem, such as liver disease, congestive heart failure or cancer.
Learn about spleen location, spleen pain and other symptoms, and possible causes and treatments for enlarged spleen (splenomegaly).
In entropion, your eyelid turns inward, causing lashes and skin to rub against the eye. Learn about causes and treatment for this irritating eye condition.
Eosinophilic esophagitis (EOE) can mimic gastroesophageal reflux disease. Here’s how the two conditions differ in cause and treatment.
Learn about this tumor that forms from ependymal cells in the brain and spinal cord. Treatments include surgery and radiation therapy.
Find out more about this usually harmless, common skin bump in adults.
Learn about this group of inherited skin diseases that often shows up in infancy and cause fragile, blistering skin. Severe forms may be life-threatening.
Understand the causes of and treatments for epididymitis, an inflammation of the coiled tube (epididymis) at the back of the testicle that stores and carries sperm.
Learn about epilepsy symptoms, possible causes of epilepsy and how epilepsy is treated, including surgical treatment options.
This rare, slow-growing soft tissue cancer tends to occur in teenagers and young adults — often in a hand, wrist, arm or leg, but it can start in other areas.
Erectile dysfunction — Comprehensive overview covers treatment, diagnosis of this common condition.
Esophageal cancer — Comprehensive overview covers symptoms, causes, treatment of cancer of the esophagus.
Esophageal spasms — Comprehensive overview covers symptoms, treatment of abnormal muscle spasms in the esophagus.
Learn how to spot and what to do if you experience signs of this serious complication of liver disease.
Learn more about the causes and treatment of inflammation of the esophagus.
This disorder can cause your body to make excess blood clots because there are too many platelets, a sticky component of blood cells.
Find out more about this disorder that causes uncontrollable shaking and learn how it differs from Parkinson's disease.
Find out about this rare cancer that begins in the upper portion of the nasal cavity. Learn about symptoms and treatments, including minimally invasive surgery.
Learn about diagnosis and treatment of this bone and soft tissue cancer, including chemotherapy, radiation, proton beam therapy and limb-saving surgery.
Exercise headaches — Comprehensive overview covers causes, treatments of this puzzling disorder.
Regular exercise is beneficial in many ways, but for some people, exercise can trigger breathing problems. Medication can help.
External compression headaches are triggered by tight headwear — but treatment is usually as simple as removing it from your head.
Many people over age 50 experience eye floaters. Learn more about this common problem, including causes, other risk factors and treatment options.
Eye melanoma is a type of eye cancer. Learn about symptoms and treatments for this rare cancer. It's also called ocular melanoma or uveal melanoma.
Gazing for long stretches at computer or digital screens is a frequent eyestrain culprit. Find out how to relieve — and prevent — this common problem.
Factitious disorder ? a serious mental disorder in which someone deceives others by appearing sick, by purposely getting sick or by self-injury.
This inherited clotting disorder can increase your chance of developing abnormal blood clots, most commonly in your legs or lungs.
Learn about the symptoms, complications and treatment of this inherited inflammatory disorder.
This inherited condition leads to colon cancer. Treatment consists of having frequent screenings and having surgery to remove all or part of the colon.
Familial hypercholesterolemia — Comprehensive overview covers signs, symptoms and treatments.
Do you see distant objects clearly, but develop a blur as they come close? This vision problem, called farsightedness, is easily corrected with prescription lenses.
Febrile seizures — these are frightening but generally harmless seizures that affect infants and young children.
Learn about this common but potentially embarrassing problem that causes some people to avoid social situations. Treatments are available.
Learn about infertility in women, including possible causes, what tests might be needed and fertility treatments available to help with getting pregnant.
Learn more about female sexual difficulties — what causes them and possible treatments, including medications.
Fetal alcohol syndrome results from alcohol exposure during the mother's pregnancy, causing irreversible brain damage and growth problems in the child.
When a baby in utereo grows much larger than average for gestational age, it can lead to complications during childbirth for both mother and baby.
Medications can lower a fever, but sometimes it's better left untreated. Fever may play a key role in helping your body fight off a number of infections.
A fibroadenoma is a type of noncancerous (benign) breast lump. Unless you have symptoms that bother you, treatment might not be needed.
Learn about this condition that's common in women, including symptoms, possible causes and testing to determine when breast cysts might need treatment.
Learn more about this condition that can narrow different arteries, including ones that supply blood to your kidneys, brain, heart or abdomen.
This complicated disorder amplifies painful sensations by affecting the way your brain processes pain signals. Medications, therapy and exercise can help.
Fibrous dysplasia — Irregular bone growths can cause pain, bone deformities or fractures. Treatments may manage pain and stabilize bones.
Flatfeet — Comprehensive overview covers causes, treatment of this often symptomless foot condition.
Learn about the symptoms of this type of cancer that forms under your tongue. Floor of the mouth cancer treatments include surgery, radiation and chemotherapy.
Learn more about how damaged hair follicles become infected. This condition may clear up on its own, but severe infections can cause scarring or hair loss.
Food allergy — Comprehensive overview covers symptoms, testing and treatment of this troublesome food reaction.
Learn more about this foodborne illness that can cause nausea, vomiting and diarrhea within hours of eating contaminated food.
Foot drop is a general term that describes a difficulty in lifting the front part of the foot. It's often caused by compression of a nerve.
In this common form of epilepsy, the seizures stem from the front of the brain. They can produce symptoms that appear to be psychiatric.
Frontotemporal dementia — Overview covers symptoms and treatment for this group of rare brain disorders that can affect behavior, speech and movement.
Learn how to prevent frostbite by preparing for being outdoors in freezing temperatures and how to treat and recover from frostbite.
Frozen shoulder — Comprehensive overview covers symptoms, causes and treatment of this painful joint condition.
Fuch's dystrophy can cause eye pain and vision problems that worsen over time. Medications can help symptoms, but surgery may offer long-term relief.
Functional neurologic disorders or conversion disorder include nervous system symptoms affecting movement or the senses that are not caused by medical disease.
Galactorrhea is a type of milky nipple discharge in people who aren't breast-feeding. Find out more about the possible causes and treatments.
Learn about this cancer that begins in the gallbladder. Treatment typically involves surgery. Chemotherapy and radiation therapy may be options.
Gallstones are hard pieces of material that can form in your gallbladder. Learn about causes and treatment for this sometimes painful digestive disorder.
Ganglion cysts — Comprehensive overview covers causes, treatment of lumps on wrist, hand or foot.
Learn more about the symptoms, diagnosis and treatment of tissue death due to a lack of blood flow or a bacterial infection.
Learn about what is normal digestive system gas, what contributes to gas, and what you can do to lessen gas or gas pains.
Gastritis, or inflammation of the stomach lining, has many possible causes. Find out how to relieve the distressing symptoms.
GERD, in which stomach acid moves into the esophagus, causes discomfort and may lead to precancerous changes in the lining of the esophagus.
Bleeding from anywhere in your digestive tract is a symptom of a disorder. Bleeding can be hidden or obvious, slight or severe.
Gastrointestinal stromal tumors (GISTs) typically develop in the stomach or small intestine, causing bleeding, anemia, nausea and similar symptoms.
Gastroparesis, often caused by diabetes, makes food move through your stomach too slowly. Symptoms include nausea and always feeling full.
An enzyme that breaks down certain fatty substances doesn't work properly in people with Gaucher disease. Enzyme replacement therapy often helps.
Excessive, ongoing anxiety and worry can interfere with your daily activities and may be a sign of generalized anxiety disorder, but treatment can help.
Genital herpes — Comprehensive overview covers symptoms, treatment of this highly contagious disease.
Genital warts — Comprehensive overview covers symptoms, treatment, prevention of this common sexually transmitted infection.
Geographic tongue may look alarming, but it doesn't cause health problems. It can sometimes cause tongue discomfort and more sensitivity to certain foods.
Gestational diabetes develops during pregnancy (gestation). It causes high blood sugar that can affect your pregnancy and your baby's health. Learn about risks, treatment and prevention.
Head pain and tenderness are the most common symptoms of giant cell arteritis, an inflammation of the lining of your arteries.
Stomach cramps, nausea and watery diarrhea could indicate a giardia infection. Find out how to treat and prevent this waterborne parasite.
This inherited liver condition affects the liver's ability to break down red blood cells. It usually has no serious medical consequences.
Gingivitis is a common and mild form of gum disease that causes irritation, redness and swelling of your gums.
Having regular eye exams can help catch glaucoma early and save your eyesight. Find out about symptoms and treatment for this vision-stealing eye disease.
Learn about this aggressive cancer that can occur in the brain or spinal cord. Glioblastoma treatments include surgery, radiation and chemotherapy.
Gliomas are among the most common types of brain cancer. Learn more about diagnosis and treatment, including innovative research to find new therapies.
Overview covers symptoms, causes and treatments for acute and chronic glomerulonephritis, a type of kidney inflammation.
Goiter — Comprehensive overview covers causes, treatment of this enlargement of the thyroid gland.
Golfers, tennis players and others who repeatedly use their wrists or clench their fingers can develop this painful condition.
Gonorrhea is a common infection that often causes no signs or symptoms. Learn more about the treatment, prevention and possible complications of this sexually transmitted infection.
This type of arthritis can cause sudden, severe attacks of pain, swelling, redness and tenderness – often in the joint at the base of the big toe.
Learn all about grand mal seizures — the type of seizure that can cause convulsions — and how to help if you see someone having one.
Learn about this chronic skin condition that affects young adults and causes reddish bumps in a ring pattern, which usually go away without treatment.
Granulomatosis with polyangiitis causes inflammation in the blood vessels in your nose, sinuses, throat, lungs and kidneys. Prompt treatment is vital.
Learn about the signs and symptoms, causes and treatment of this immune system disorder that results in the overproduction of thyroid hormones (hyperthyroidism).
Greenstick fractures — Comprehensive overview covers symptoms, diagnosis and treatment of this childhood bone injury.
This common bacterium, usually harmless in healthy adults, can cause serious illness in newborns and adults with certain chronic conditions, such as diabetes.
Learn about this common condition involving leg pain in children, including growing pain symptoms and how to ease discomfort.
Growth plate fractures — This common childhood bone injury often needs immediate treatment as it can result in a shorter, longer or crooked limb.
Learn about symptoms, diagnosis and treatment for Guillain-Barre syndrome — a rare disorder that affects the nerves.
Learn more about this potentially life-threatening infection that spreads through blood, sex and childbirth. Know how to prevent and treat it.
This common viral infection often gets better on its own, but when it doesn't, it may cause a variety of warts and can even lead to some cancers.
This common and sometimes stressful condition may result from heredity, medications or medical conditions. Treatment may reverse or slow hair loss.
This slow-growing cancer doesn't always need immediate treatment. Learn how doctors decide to start chemotherapy and biological therapy for hairy cell leukemia.
Hammertoe and mallet toe — Comprehensive overview covers causes, symptoms and treatment of these foot deformities.
Hamstring injury — Comprehensive overview covers symptoms, treatments, self-care, prevention of this leg muscle injury.
Learn about the symptoms, treatment and prevention of this contagious viral infection that's common in young children and characterized by sores in the mouth and a rash on the hands and feet.
Unpleasant signs and symptoms can develop after drinking too much alcohol — but severe signs may indicate alcohol poisoning, a life-threatening emergency.
Hantavirus pulmonary syndrome is a severe, sometimes fatal, lung infection characterized by flu-like symptoms that can progress rapidly.
Hashimoto's disease — Comprehensive overview covers symptoms, treatment of this cause of thyroid gland inflammation.
Find out more about how to diagnose and get relief from this common condition that can make you feel awful, seasonally and year-round.
Head lice — Learn more about causes, treatment and prevention of infestation of these tiny insects that feed on blood from the human scalp.
Headaches in children aren't usually serious, and can often be managed with medications and healthy habits.
Age- and noise-related hearing loss are common and can affect quality of life. But many treatments are available.
Heart arrhythmia — Comprehensive overview covers symptoms, causes, treatment of this common heart disorder.
A blockage of blood flow to the heart causes a heart attack, which can damage or destroy heart muscle.
Learn about symptoms, causes and treatment of heart disease, a term describing a wide range of conditions that can affect the heart.
Heart failure is a chronic disease that needs lifelong management. Treatments can help you live longer and can even strengthen the heart in some cases.
Learn about symptoms, causes and treatments of abnormal heart sounds.
Stress, exercise, medication or, rarely, a medical condition can trigger heart palpitations — the feeling of your heart fluttering or pounding rapidly.
Learn about heart valve disease, a condition in which one or more of your heart valves doesn't work properly.
Occasional heartburn is a common, manageable condition — but when is it a problem?
An overheated body can lead to dangerous symptoms. Get tips to prevent heat exhaustion and how to cool down quickly when it happens.
Learn more about the symptoms, causes and treatment of this heat-related problem of the skin that affects people of all ages.
Untreated heatstroke can cause permanent damage and even death. Learn how to prevent this medical emergency — and what to do right away when it occurs.
Helicobacter pylori (H. pylori) infection — Comprehensive overview covers symptoms, treatment of infection with Helicobacter pylori bacteria.
Learn more about the causes and treatment of this red mark on the skin of babies that fades over time.
Hemochromatosis — Comprehensive overview covers symptoms, causes and treatment of this inherited liver disorder.
Damage to the small blood vessels in the kidneys can cause clots that clog the organ’s filtering system. This can lead to life-threatening kidney failure.
In this inherited disorder, your blood lacks one of several clot-forming proteins. The result is prolonged bleeding, which can be life-threatening.
There are many effective options for easing the discomfort of hemorrhoids — swollen veins in your anus and lower rectum.
Learn about the symptoms, causes and treatment of this blood vessel disease, also called IgA vasculitis, that causes a purplish rash on the lower legs.
Hepatitis A is a contagious liver infection caused by a virus. Learn more about its symptoms, treatment and prevention, including hepatitis A vaccine.
Hepatitis B is a contagious liver infection caused by a virus. It may become long lasting. Know the symptoms, treatment and prevention of hepatitis B.
Many people with hepatitis C don't even know they're infected. Find out about symptoms and treatment for this potentially dangerous liver disease.
Learn about innovative treatments for the most common type of liver cancer (hepatocellular carcinoma, or HCC), including liver transplant and ablation.
This inherited blood vessel disorder can cause severe nosebleeds, strokes, bleeding in the digestive tract and anemia.
Herniated disks occur most often in the lower back. In many cases, they cause no symptoms and require no treatment. Surgery is required very rarely.
A hiatal hernia occurs when part of the stomach bulges into the chest. It can cause severe heartburn but is treatable.
Caused by contractions of your diaphragm, hiccups are usually harmless. But rarely, hiccups may be a sign of an underlying medical problem.
Learn more about the causes, symptoms and treatments of this long-term condition that causes painful lumps and tunnels under the skin.
Learn about the symptoms, treatment and prevention of a condition in which the force of blood against artery walls is too high (hypertension).
Children can develop high blood pressure for the same reasons adults do — excess weight, poor nutrition and lack of exercise.
You need some cholesterol in your blood to build healthy cells. But high cholesterol can increase your risk of heart disease. Lifestyle changes can help.
Hilar cholangiocarcinoma — Overview covers diagnosis, treatment of hilar cholangiocarcinoma type of bile duct cancer.
In infancy, this condition often can be corrected with a soft brace. Older children and young adults might require surgery to correct the misalignment.
Your risk of hip fracture increases as you age, often related to weakening bones. Get hip to lifestyle changes that can keep your bones strong and reduce your hip fracture risk at any age..
Sports such as golf, softball and ice hockey can increase your risk of damaging the ring of cartilage that helps cushion and stabilize your hip joint.
This digestive disorder that's present at birth affects the nerves in the colon. It causes severe constipation but can be treated.
Hirsutism — Comprehensive overview covers symptoms, complications, treatment of unwanted excess hair in women.
Learn more about the symptoms, treatment of this sometimes life-threatening fungal disease caused by spores in bird and bat droppings.
Hives and angioedema — Learn more about these common skin conditions and their symptoms, causes, treatment and home remedies. Includes photos.
Hoarding disorder is a persistent difficulty discarding or parting with possessions because of a perceived need to save them.
Learn more about risk factors, treatment and how this cancer differs from other lymphomas.
An interruption in the nerve signals from the brain to the eye causes Horner syndrome, affecting the eye and face on one side.
Hot flashes are common during the menopausal transition. Learn about strategies for relief of hot flashes, including hormone therapy and natural remedies.
This rare metabolic disorder can affect the lungs, heart, joints, connective tissue, brain and nervous system. Treatments may help complications.
Huntington's disease causes a progressive breakdown of nerve cells in the brain. Find out about symptoms, diagnosis and treatment.
Learn about this rare type of aggressive thyroid cancer. Treatment typically involves surgical removal of the thyroid gland.
Find out more about the symptoms, causes and possible treatments for this swelling in the scrotum.
Read more about this potentially fatal disorder that causes fluid buildup in the brain — resulting in symptoms ranging from headaches to poor balance.
Hydronephrosis occurs when urine doesn't drain properly from the upper urinary tract, leading to kidney swelling. Severe hydronephrosis requires treatment.
Hypercalcemia can weaken your bones, create kidney stones, and interfere with how your heart and brain work. Treatment depends on the cause.
Hypereosinophilic syndrome refers to a group of related blood disorders. Find out about treatment of and research on them.
Hyperglycemia in diabetes can occur for many reasons. Know the causes, symptoms and treatments of high blood sugar and when to get emergency help.
Learn more about causes, symptoms, treatment and self-care tips for this embarrassing condition that causes heavy sweating unrelated to heat or exercise.
Learn about symptoms, causes, diagnosis and treatment for this rare kidney disorder, which develops in people who have too much oxalate in the urine.
Learn about symptoms, tests and treatment for hyperparathyroidism — a condition caused by overactivity of the parathyroid glands.
Learn more about the consequences of an overactive thyroid, along with various treatment options available for this condition.
Learn about this heart disorder in which the heart muscle becomes abnormally thick, which makes it harder for the heart to pump blood.
Low blood sugar can cause uncomfortable symptoms such as dizziness and confusion, and can quickly become serious if left untreated.
Hyponatremia is the term used when your blood sodium is too low. Learn about symptoms, causes and treatment of this potentially dangerous condition.
Learn more about this uncommon condition in which your body secretes abnormally low levels of parathyroid hormone (PTH), which is key to regulating your body's levels of calcium and phosphorus.
Learn about the symptoms and treatment of this rare hormonal disorder caused by a problem with the pituitary gland.
Learn more about this rare congenital heart condition that results in underdevelopment of the left side of the heart.
Hypospadias is a birth defect in which the opening of the urethra is located on the underside of the penis instead of the tip. Learn about treatment.
Learn how to help in this life-threatening situation in which someone's body is losing heat faster than it can generate it.
Feeling sluggish? Gaining unexpected weight? Your thyroid gland may not be working effectively. Learn more about causes and treatments of this condition.
Ice cream headaches can cause brief, stabbing pain when you eat or drink something cold, or expose your head to sudden cold.
Ichthyosis vulgaris — Comprehensive overview covers signs, symptoms, causes, diagnosis and treatment.
Idiopathic hypersomnia is a sleep disorder that causes you to be excessively sleepy during the day and to have trouble waking up from sleep.
This disease causes kidney inflammation that, over time, can interfere with your kidneys' ability to filter waste from your blood.
Excessive worry that you're seriously ill based on minor symptoms can result in major emotional distress and disrupt your life. Also called hypochondria.
Caused by low levels of platelets, symptoms may include purple bruises called purpura, as well as tiny reddish-purple dots that look like a rash.
Impacted wisdom teeth — Learn about symptoms, complications and treatment of impacted wisdom teeth.
Impetigo — Comprehensive overview covers symptoms, causes, treatment of this highly contagious skin condition.
Sometimes the cervix opens and thins early, making it unable to support a pregnancy. Learn more about this difficult-to-diagnose condition.
Is it indigestion or something else? Found out about causes, symptoms and treatment for this common digestive disorder.
Learn about this common condition in newborns, especially those born preterm. With close monitoring and light therapy, complications are rare.
This common and messy condition is usually harmless. Most babies outgrow it by age 18 months.
Viruses, bacteria, fungi and parasites can all cause infection. Find out more about how to prevent and treat these conditions.
Find out about the challenges of infertility, when to see a doctor, causes, risk factors, and treatments including insemination and in vitro fertilization.
Chronic diarrhea and belly pain could result from inflammatory bowel disease. Learn about IBD causes, diagnosis and treatment.
Learn about this rare, aggressive type of breast cancer that causes a red, swollen breast. Treatments include surgery, radiation, chemotherapy and others.
Learn more about the symptoms, causes and prevention of this potentially fatal viral infection that attacks the respiratory system.
Learn about causes, treatment and prevention of this common, painful skin condition — sometimes called razor bumps — often affecting black men who shave.
Learn about causes, prevention and treatment of this common, painful nail condition that usually affects the big toe.
What happens if part of the intestine bulges through a weak spot in abdominal muscle? This condition can be painful and often requires surgery to fix.
Insomnia is a disorder that can make it hard to fall asleep, hard to stay asleep, or cause you to wake up too early and not be able to get back to sleep.
This mental disorder involves repeated, sudden episodes of impulsive, aggressive, violent behavior or verbal outbursts that cause major distress in life.
Bladder pain and urinary frequency flare with certain triggers if you have this condition. Learn about treatments and self-care.
In interstitial lung disease, progressive lung can cause permanent breathing problems. Learn the causes, including many toxins in the environment.
Learn more about what happens when blood flow to part of the digestive system is reduced, and how this serious condition is treated.
Intestinal obstruction — Comprehensive overview covers causes, symptoms, diagnosis and treatment of this serious disorder.
A collection of blood within the skull, known as an intracranial hematoma, is a serious, possibly life-threatening, complication of head trauma.
Intracranial venous malformations are abnormally enlarged veins in your brain. Find out more about diagnosis and treatment of this neurological condition.
Intussusception — Comprehensive overview covers symptoms, diagnosis, treatment of this rare but serious intestinal disorder.
Breast cancer that begins in the milk-producing glands of the breast is uncommon. Learn what sets lobular carcinoma apart from other breast cancer types.
Iritis — Comprehensive overview covers symptoms, causes, treatment of this inflammation of the eye's iris.
Iron deficiency anemia — Comprehensive overview covers symptoms, causes, treatment of this blood disorder.
Find out about irritable bowel syndrome symptoms and diagnosis. Often, lifestyle changes help manage this common, chronic bowel disorder.
This condition occurs when the arteries supplying blood to the colon become blocked. It can cause serious complications but usually subsides on its own.
Learn about causes of this common irritating skin condition and which treatments and self-care measures may provide relief.
Learn more about prevention and first aid for these painful injuries that are common among people swimming in seawater and are rarely life-threatening.
Jetting across time zones can take a toll on your body's internal clock. Here's how to cope with fatigue and other symptoms while traveling.
Jock itch — Comprehensive overview covers symptoms, treatment of this fungal infection affecting more than athletes.
Juvenile fibromyalgia — Comprehensive overview covers symptoms, treatment of this chronic condition characterized by widespread pain.
Juvenile idiopathic arthritis (JIA) was formerly known as juvenile rheumatoid arthritis. JIA can cause growth problems, joint damage and eye inflammation.
Kaposi's sarcoma, a cancer caused by a virus, occurs in AIDS and in transplant patients taking anti-rejection drugs. It appears as purplish skin spots.
Learn more about this condition that primarily affects children and causes inflammation in the walls of the arteries throughout the body.
An inflamed, red eye could mean you have keratitis. Find out how to spot and treat this potentially dangerous eye problem.
Keratoconus occurs when your cornea bulges outward, causing vision problems. Find out about symptoms, causes and treatment for this eye condition.
Keratosis pilaris — Comprehensive overview covers causes, symptoms and treatments of this bumpy skin condition.
Learn about the diagnosis, symptoms and treatment of kidney cancer, including renal cell carcinoma.
Kidney cysts — round pouches of fluid on or in the kidneys — are sometimes discovered during routine imaging exams. Learn when treatment may be needed.
A urinary tract infection that travels to your kidneys can be dangerous. Seek prompt medical treatment if you develop signs and symptoms.
Kidney stones — Comprehensive overview covers symptoms, risks, causes, treatment of this often intensely painful condition.
Kleptomania is the recurrent inability to resist urges to steal items that you generally don't really need and that usually have little value.
Klinefelter syndrome is a genetic disorder that results when a male is born with an extra copy of the X chromosome. Learn about diagnosis and treatment.
Klippel-Trenaunay syndrome is a rare birth (congenital) condition that affects the development of blood vessels, soft tissue and bones.
Knee bursitis is inflammation of a small fluid-filled sac (bursa) situated near your knee joint. Knee bursitis causes pain and can limit your mobility.
This common complaint can result from an injury or medical condition. Physical therapy and braces can help, but sometimes surgery is needed.
Find out more about this rare, inherited condition that damages nerve cells. Krabbe disease typically causes worsening signs and symptoms starting in infancy.
This exaggerated, forward rounding of the back is often caused by osteoporosis in older women. Spinal malformations can cause kyphosis in infants or teens.
Lactose intolerance — Comprehensive overview covers symptoms, causes, diet and self-care.
Learn about the symptoms, causes and treatment for this common irritation of the voice box.
Latex allergy — a reaction to proteins in natural rubber latex, found in many medical products — can be a medical emergency.
Abnormal visual development early in life can cause reduced vision in one eye, which often wanders inward or outward.
Learn about lead poisoning symptoms and treatment of lead exposure in children and adults. Explore ways to keep your kids safe from lead exposure.
Learn more about the causes and treatment of this heart condition in which the walls of your heart's main pumping chamber are enlarged and thickened.
This childhood condition occurs when blood supply is temporarily interrupted to the ball part of the hip joint, making it fracture easily and heal poorly.
Bacteria that can live in water from air conditioning systems, showers and spas cause this severe form of pneumonia.
This rare type of cancer affects smooth muscle tissue, most commonly in the abdomen, blood vessels and skin. Surgical removal is the primary treatment.
Learn about this cancer that forms in the blood and bone marrow.
Leukoplakia appears as thickened, white patches on your gums, cheeks and bottom of your mouth that can't be scraped off.
This common dementia is caused by a buildup of proteins in the brain, and it affects thinking, memory and motor control.
Learn about how to get rid of these tiny, wingless, parasitic insects and keep them from coming back.
Lichen nitidus — Comprehensive overview covers symptoms, treatment of this harmless skin condition.
Learn about the causes, symptoms and treatment of this skin condition that causes swelling and irritation in the skin, hair, nails, mouth and vagina.
Learn more about the causes, symptoms, complications, treatment and self-care tips for this blotchy skin condition that affects the genital and anal areas.
Limited scleroderma can affect your skin, digestive tract, heart, lungs or kidneys. Treatment focuses on managing symptoms and preventing complications.
Lip cancer often appears as a sore on your lip that doesn't heal. Learn about lip cancer treatments, including surgery, radiation and chemotherapy
Lipoma — Comprehensive overview covers symptoms, causes, treatment of this usually harmless fatty tumor that tends to show up in middle age.
Learn about diagnosis and treatment options for this type of soft tissue sarcoma that forms from fat cells.
Listeria infection is a foodborne bacterial illness that can be very serious for some people. Learn about symptoms, treatment and tips for prevention.
Learn how doctors use surgery, liver transplant, radiation, chemotherapy and other methods to treat hepatocellular carcinoma and other types of liver cancer.
Liver problems — Comprehensive overview covers symptoms, causes, prevention of liver diseases and conditions.
A liver hemangioma is a noncancerous mass that typically doesn't need treatment. Find out more about this common liver condition and when to get treatment.
If a breast biopsy reveals you have LCIS, your risk of breast cancer is increased. Learn how you can reduce your risk through medications and other strategies.
Learn more about the causes and treatment of this heart rhythm condition that can potentially cause fast, chaotic heartbeats.
Low blood pressure (hypotension) — Comprehensive overview covers symptoms, causes and treatment of this condition.
Many women experience a low sex drive at some point. But you can get your desire back. Learn about the diagnosis and treatment of lost libido in women.
Having a low sperm count can make conceiving a child difficult, but not necessarily impossible. Find out about possible causes and treatment.
Learn about the approaches doctors take to treating this deadly form of cancer, including minimally invasive surgery, targeted therapy and immunotherapy.
Inflammation caused by lupus can affect your joints, skin, kidneys, blood cells, brain, heart and lungs. Treatment focuses on symptom control.
Learn about this common lupus complication affecting the kidneys, including symptoms to watch for, how it's diagnosed and what treatments are available.
The most common tick-borne illness in North America and Europe, Lyme disease is caused by the bite of an infected tick.
Damaged or removed lymph nodes can affect how lymph fluid drains. Fluid buildup leads to swelling. Treatments include exercises, compression and massage.
Cancer that forms in the germ-fighting lymphatic system is called lymphoma. Types of lymphoma include Hodgkin's lymphoma and non-Hodgkin's lymphoma.
Learn about this disorder caused by inherited genetic mutations that increases the risk of colon cancer, endometrial cancer and other forms of cancer.
Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency — Comprehensive overview covers signs, symptoms and treatments of this inherited disorder.
MRSA infections often occur in health care settings, but they can happen anywhere. Find out about symptoms and treatment for this virulent staph infection.
Learn about the symptoms, causes, treatment, and prevention of this infectious disease transmitted to humans through mosquito bites.
Breast cancer can affect anyone, including men. Learn about the signs and symptoms of this cancer. Treatment most often involves surgery.
Male hypogonadism — Comprehensive overview covers symptoms and treatment of testosterone deficiency.
In over a third of couples unable to conceive, male infertility plays a role. Find out what causes male infertility and available options for treatment.
Malignant hyperthermia — Comprehensive overview covers signs, symptoms and treatments of this severe reaction to certain drugs.
MPNSTs are cancers that form in the linings of nerves. Treatment includes surgery, radiation therapy and, sometimes, chemotherapy.
Mammary duct ectasia is a noncancerous breast condition that affects the milk ducts. Learn the signs and symptoms and when treatment might be needed.
This inherited disorder affects the skeleton and eyes. It can also harm the large blood vessel that carries blood from your heart to the rest of your body.
Redness, pain and swelling in your breast could be mastitis — inflammation of breast tissue. Find out about mastitis symptoms, treatment and self-care.
Learn about this vaccine-preventable disease that used to be common in childhood and is well known for a characteristic red, splotchy rash and high fever.
When medications that ease headache pain are used too often, these drugs can actually start causing headaches. Learn about prevention and treatment.
Medulloblastoma is the most common cancerous brain tumor in children. Treatment usually includes a combination of surgery, radiation and chemotherapy.
Melanoma — Comprehensive overview covers symptoms, treatment of this most serious type of skin cancer.
Membranous nephropathy is a sometimes silent kidney problem. But it can be serious. Learn the symptoms, treatment and how clinical trials may help.
This chronic disorder affects balance and hearing, causing unpredictable episodes of dizziness and hearing problems.
Meningioma is the most common type of tumor that forms in the head and may affect the brain. Find out about meningioma symptoms, diagnosis and treatment.
Spot the signs and understand the treatment options for meningitis, an infection that has several possible causes.
Find out how this biological change impacts your daily life and health — and how to manage your symptoms.
Heavy periods or irregular periods can be annoying and disrupt your life. Learn about treatments that can help with menstrual cycle problems.
Menstrual cramps — pain in the lower abdomen just before or during menstrual periods — can range from mild to severe. Learn about treatment options.
A wide range of mental health conditions affect mood, thinking and behavior and can make you miserable and cause problems in daily life.
Meralgia paresthetica — Comprehensive overview covers symptoms, causes and treatments of this compressed nerve condition.
Learn about this aggressive skin cancer. Find out about symptoms, diagnosis and treatments, including Mohs surgery, radiation and immunotherapy.
Mesenteric ischemia can come on suddenly or develop over time. Find out more about this condition that restricts blood flow to the small intestine.
This painful condition, which involves inflamed lymph nodes in the membrane that connects your bowel to your abdominal wall, usually affects children and teens.
Learn about this uncommon cancer that's linked to asbestos exposure. Mesothelioma treatments include surgery, radiation and chemotherapy.
Having three or more specific risk factors, such as high blood pressure or abdominal fat, boosts your risk of type 2 diabetes and heart disease.
Metachromatic leukodystrophy — Find out more about this rare hereditary disorder that causes fatty substances to build up in your nervous system.
Metatarsalgia is a condition in which the ball of your foot becomes painful and inflamed. Learn about the causes, treatments and prevention of this injury.
When an infant's head is smaller than expected, it may be microcephaly — a brain abnormality that often develops in the womb and affects child development.
Persistent, watery diarrhea could be a sign of microscopic colitis. Find out about testing and treatment for this inflammatory disorder of the colon.
These painful, recurring headaches can last hours to days, often accompanied by nausea, vomiting, and sensitivity to light and sound.
This type of migraine causes not just pain but also sensory disturbances (aura), such as flashes of light, blind spots or tingling in your hand or face.
Learn more about this stage between the normal cognitive decline of aging and the more serious decline of dementia.
Milia — Comprehensive overview covers symptoms, causes, treatment of this newborn complexion problem.
Find out what happens when the immune system reacts abnormally to proteins in milk, causing allergic signs and symptoms such as hives and wheezing.
Learn about miscarriage symptoms, what might cause a miscarriage and how to cope with pregnancy loss.
Learn more about diseases that affect the heart valve between left heart chambers.
Learn about this heart condition that occurs when the mitral valve's leaflets bulge (prolapse) into the heart's left upper chamber (left atrium).
Learn more about the symptoms, diagnosis and treatment of this condition in which the heart's mitral valve leaks backward.
Learn about symptoms, causes and treatment of mitral valve stenosis, a condition in which your heart's mitral valve doesn't open properly.
Some women experience pain on one side of the lower abdomen midway through their menstrual cycles. This cyclic pelvic pain is known as mittelschmerz.
Mixed connective tissue disease has signs and symptoms of multiple disorders, making it difficult to diagnose. There's no cure, but medications can help.
Molar pregnancy is a rare complication that requires early treatment. Learn more about diagnosis and treatment of this type of pregnancy loss.
Coughing, sneezing and itchy eyes often accompany a mold allergy. Find out how to treat this common condition and help keep it under control.
Learn about moles (nevi), what causes them, whether they put you at increased risk of skin cancer and how to check a mole for signs of skin cancer.
Learn how to prevent and treat this common skin infection that affects people of all ages.
This condition happens when your bone marrow produces an abnormal protein in your blood. It can sometimes progress to certain types of blood cancer.
Learn about the symptoms and treatment of the kissing disease in adults and children.
Learn more about pregnancy-related nausea and vomiting, along with remedies that may help ease that queasy feeling.
Learn more about this rare, painless skin condition, including risk factors, symptoms, complications and treatment.
Morton's neuroma: Comprehensive overview covers diagnosis, causes, treatment for this painful foot disorder.
Mosquito bites — Comprehensive overview covers prevention, treatment and role in disease transmission.
Learn what doctors and dentists look for when diagnosing mouth cancer. Find out about oral cancer treatments, including surgery, chemotherapy and radiation.
Moyamoya disease — Learn more about moyamoya disease diagnosis and treatment.
Learn about this cancer that forms from white blood cells called plasma cells. Multiple myeloma treatments include medications and bone marrow transplant.
This nervous system disorder causes a range of symptoms — and while there's no cure, it's possible to have long periods of remission.
Multiple system atrophy — Comprehensive overview covers symptoms, causes, treatment of this neurological disorder.
Find out more about the symptoms and treatment of this viral illness and how vaccination prevents it.
Muscle cramp — Comprehensive overview covers causes, treatment, prevention of cramped muscles.
Minor strains may only overstretch a muscle or tendon, while more severe injuries may involve partial or complete tears in these tissues.
Read about different types of this progressive disease that interferes with the creation of new muscle, as well as treatments to help with symptoms.
A breakdown in the communication between nerves and muscles causes weakness and fatigue of muscles under your voluntary control.
Learn how medications and bone marrow transplants are used to control complications caused by these syndromes that affect the bone marrow.
Find out about this bone marrow cancer. Learn about diagnosis and treatments, including bone marrow transplant, for myelofibrosis and primary myelofibrosis.
Myocardial ischemia reduces blood flow to the heart and may cause chest pain – but not always. Learn all the signs and symptoms and how to treat it.
Learn about the diagnosis and treatment of this inflammation of the heart muscle that can affect the heart muscle and the heart’s electrical system.
This usually harmless condition involves uncontrollable jerking motions, such as hiccups and "sleep starts."
In this condition, pressure on trigger points can cause persistent pain in the muscle itself and sometimes in seemingly unrelated parts of your body.
Myxofibrosarcoma is a cancer that occurs mainly in older people. The leg, arm or trunk is the most common site. The risk of recurrence is high.
Naegleria infection is caused by an amoeba commonly found in fresh water. Learn what symptoms to look for in this rare, often fatal infection.
Learn about symptoms, treatment and prevention of this common infection among older adults that causes nails to discolor and crumble.
This mental health disorder includes an inflated sense of importance, a deep need for excessive admiration, fragile self-esteem and troubled relationships.
Learn more about this sleep disorder that causes periods of involuntary sleep, sleep paralysis and early rapid eye movement (REM) sleep.
Nasal polyps are painless, noncancerous growths that can lead to a lost sense of smell or infection. Medication or surgery can help.
Nasopharyngeal carcinoma is cancer that occurs in the nasopharynx, which is located behind your nose and above the back of your throat.
Tired of squinting at objects in the distance? There are many effective treatment options for nearsightedness, and some preventive options emerging.
Neck pain — Comprehensive overview covers causes of neck pain and neck pain relief options.
Learn about symptoms, risk factors and possible treatments for this rare disorder in people with advanced kidney disease.
Swelling around your feet and ankles, and maybe even your eyes, is a common sign of this condition that occurs when your kidneys excrete too much protein.
Learn more about the symptoms, diagnosis and treatment of neuroblastoma, one of the most common cancers of childhood.
Learn more about this itchy skin condition that can disrupt your sleep and daily activities. Successful treatment depends on resisting the urge to scratch.
Learn about the types of tumors that make up this group of rare cancers. Find out about symptoms, causes, diagnosis and treatments.
Neurofibroma is a noncancerous nerve tumor that can appear anywhere in the body, forming soft bumps on or under the skin. Treatment may involve surgery.
This genetic disorder causes tumors on nerve tissue, but surgery and other therapies can manage pain and other symptoms.
Understand more about this condition that affects the spinal cord and eye nerves, and is sometimes mistaken for multiple sclerosis.
Nickel allergy, often caused by nickel in jewelry, is a form of contact dermatitis. Things like coins and zippers may also provoke nickel allergy.
Nicotine dependence — learn how nicotine produces addiction and how treatment with medications and counseling can help you end your dependence.
Niemann-Pick — Learn more about this inherited disease that mainly affects children, causing malfunction of the nerves, brain and other organs.
Nightmare disorder involves disturbing or scary dreams that awaken you, causing distress or preventing adequate sleep.
Non-Hodgkin's lymphoma — Learn more about the symptoms, risk factors and treatment of this cancer of the lymphatic system that causes swollen lymph nodes.
Nonalcoholic fatty liver disease is becoming more common in the Western world. Find out how to treat and prevent this potentially dangerous liver disease.
This comprehensive overview covers symptoms, causes and treatment of this bothersome condition.
Learn about treatment options for all types of nonmelanoma skin cancer, including squamous cell carcinoma, basal cell carcinoma and others.
Nonulcer stomach pain is burning stomach pain or other ulcer symptoms with no detectable cause. A range of treatments can offer relief.
Noonan syndrome is a genetic disorder that may cause unusual facial features, short stature, heart defects, eye conditions and other health problems.
Norovirus is a highly contagious virus that causes vomiting and diarrhea. Learn more about the symptoms and ways to protect yourself.
Obesity isn't just a cosmetic concern. It is a medical problem that increases your risk of heart disease, diabetes and certain cancers.
Obsessive-compulsive disorder (OCD) features a pattern of unreasonable thoughts and fears (obsessions) that lead to repetitive behaviors (compulsions).
Learn the signs that point to this common and potentially serious sleep disorder and find out the treatments that can help you sleep better.
Dust, fumes and other substances you come into contact with at work can cause asthma. Find out how to recognize this common type of asthma.
Ocular rosacea — Comprehensive overview covers symptoms, causes and treatments of this eye disease.
Learn about this type of tumor that can occur in the brain or spinal cord.
ODD is a childhood mental health disorder that includes frequent and persistent anger, irritability, arguing, defiance or vindictiveness toward authority.
Optic neuritis — Learn more about symptoms, causes, treatment of this painful eye disorder that affects adults under 40. Often improves without treatment.
Oral lichen planus — Learn about this chronic inflammatory condition that affects mucous membranes inside your mouth.
Oral thrush is a fungal infection caused by the overgrowth of Candida albicans, which causes creamy white lesions on the tongue and lining of your mouth.
Find out about the symptoms and causes of this inflammation of one or both testicles.
Find out more about symptoms, causes and treatment of this form of low blood pressure that happens when you stand up from sitting or lying down.
Osgood-Schlatter disease can cause a painful, bony bump just below the knee. It usually occurs in athletic children having growth spurts during puberty.
This most common form of arthritis mainly affects joints in your hands, knees, hips and spine. There's no cure, but symptoms can be managed.
Osteochondritis dissecans most commonly affects children who are very active in sports. Learn about the symptoms and treatment of this joint condition.
Caused by a severe vitamin D deficiency, osteomalacia softens bones. Children may experience leg bowing. Boosting vitamin D intake can cure the disorder.
Bones don't easily get infected, but certain situations, such as a serious injury, bloodstream infection or surgery, may lead to a bone infection.
Fractures associated with this bone-weakening condition can be life-altering. Good nutrition, regular exercise and medications can help.
Learn about the symptoms, diagnosis and innovative treatment of this bone cancer in children, including chemotherapy, limb-sparing surgery and rotationplasty.
Find out what symptoms are caused by this type of cancer, and learn about treatments, including surgery, chemotherapy and targeted therapy.
Many women have ovarian cysts at some time. Most are harmless, but some can cause serious symptoms. Know what symptoms to watch for.
OHSS can lead to painful, swollen ovaries. Learn why OHSS sometimes happens during fertility treatments and how to recognize OHSS signs and symptoms.
Frequent, sudden urges to urinate may point to overactive bladder or urinary incontinence. Learn how you can get relief from your symptoms.
This condition usually occurs in the pelvis, skull, spine and legs. It can make bones fragile and misshapen. Osteoporosis drugs are the main treatment.
Paget's disease of the breast — Comprehensive overview covers symptoms, treatment of this rare breast cancer.
Painful intercourse can occur in women for various reasons, ranging from physical problems to emotional concerns. Medications or other therapies may help.
Learn about symptoms, risk factors, prevention, diagnosis, surgery, chemotherapy and other treatment for this serious condition affecting the pancreas.
Pancreatic cysts — Comprehensive overview covers symptoms, treatment and causes of cysts in the pancreas.
Pancreatitis can occur suddenly or build up over time. Learn about symptoms, causes and treatment of this potentially serious digestive system disorder.
Learn about effective treatment for sudden episodes of intense fear that trigger severe physical reactions when there is no real danger or apparent cause.
Learn about this rare tumor that begins in nerve cells and sometimes causes high blood pressure. It's usually benign but sometimes spreads.
Paraneoplastic syndromes — Comprehensive overview covers symptoms, treatment of rare neurological disorders associated with cancer.
There's no cure for this progressive movement disorder, but treatments can help significantly improve your symptoms.
Learn more about the signs and symptoms, diagnosis, and treatment of this most common type of salivary gland tumor.
Learn more about this condition in which some of the pulmonary veins attach to other parts of the heart or veins instead of to the heart's left atrium.
Learn more about the symptoms, causes, treatment and prevention of this common childhood infection — sometimes called slapped-cheek disease.
Jumper's knee — a common knee injury — affects the tendon that stretches from the kneecap (patella) to the shinbone.
Patellofemoral pain syndrome — Comprehensive overview covers symptoms, treatment of this knee condition common among runners.
Learn about symptoms, causes and treatment of patent ductus arteriosus, a common — and treatable — heart defect that occurs shortly after birth.
Learn more about the causes and complications of this condition in which a hole in the heart doesn't close the way it should after birth.
This is one of the most common and dangerous food allergies, and it's occurring more often in children.
Pectus excavatum causes the breastbone to sink into the chest. This can affect the function of the heart and lungs. Surgery helps correct the deformity.
Pediatric brain tumors include medulloblastoma, glioma, embryonal tumor, germ cell brain tumor, spinal cord tumor, craniopharyngioma and pineoblastoma.
If your child's breathing becomes repeatedly blocked during sleep — either partially or completely — pediatric obstructive sleep apnea could be the cause.
Find out about the symptoms, causes and treatment of this infection of the female reproductive organs.
Learn about symptoms, causes, treatment and self-care tips for this group of rare conditions that causes blisters and sores on the skin or mucous membranes.
Understand the importance of an accurate diagnosis for penicillin allergy and the best practices for antibiotic treatment options.
This common condition, caused by a bacterial infection in the stomach, is usually curable with antibiotics. Sometimes, acid-reducing drugs are also needed.
Pericardial effusion — Overview covers symptoms, causes and treatment of excess fluid around the heart.
Learn about symptoms, diagnosis and treatment for pericarditis — a condition involving inflammation of tissue surrounding the heart.
Discover effective treatments and learn self-care strategies for hot flashes, night sweats, vaginal dryness and other perimenopause symptoms.
Periodontitis is a serious gum infection that damages the soft tissue and destroys the bone that supports your teeth.
Learn more about this common circulatory condition, often first signaled by leg pain when walking. Lifestyle changes and medications can help.
Peripheral nerve injuries -- Find out more about injuries affecting the peripheral nerves that link your brain and spinal cord to the rest
Learn more about growths that form on nerves connecting to the spinal cord. Surgery is the most common nerve tumor treatment.
Learn what may cause the prickling, tingling or numb sensations of nerve damage and how to prevent and treat this painful disorder.
Peritonitis — Comprehensive overview covers causes, symptoms, treatment of this abdominal infection.
Also called dysthymia, this chronic form of depression may cause you to lose interest in life, feel hopeless, lack productivity and have low self-esteem.
A personality disorder is a mental disorder involving a rigid and unhealthy pattern of thinking, functioning and behaving.
Pet allergy — Comprehensive overview covers symptoms and treatment of allergy to some pets.
Understand what causes bent and painful erections, and learn what treatments are available.
Read about this puzzling condition that causes people to feel pain where a part of the body has been amputated. A number of treatments are available.
PKU is caused by a defect in the gene that helps create an enzyme needed to break down phenylalanine. Treatment includes a lifelong low-phenylalanine diet.
Pheochromocytoma — Comprehensive overview covers symptoms, causes, treatment of this rare adrenal gland tumor.
Pilonidal cyst — Comprehensive overview covers causes, symptoms and treatments of this skin abnormality.
Pinched nerve — Comprehensive overview covers symptoms, causes, treatments of a compressed nerve.
Learn about this rare cancer that begins in the brain's pineal gland. Pineoblastoma treatments include surgery, radiation therapy and chemotherapy.
Pink eye (conjunctivitis) is uncomfortable and contagious, but — like the common cold — rarely requires medication or staying home.
Learn more about the symptoms, treatment and prevention of this common type of intestinal worm infection.
Learn more about the symptoms, causes and treatment of these abnormal growths that develop in your pituitary gland.
Pityriasis rosea — Comprehensive overview covers symptoms, causes and treatment of this common skin condition.
During pregnancy, if part of the placenta grows too far into the uterine wall, it can remain attached after childbirth, causing severe maternal blood loss.
Learn what to watch for and what to expect if you have placenta previa, a potentially dangerous pregnancy complication.
Placental abruption is a serious complication of pregnancy in which the structure that nourishes the growing baby detaches from the uterus before delivery.
Learn about the symptoms, risk factors, and treatment of this extremely rare, potentially fatal infectious disease transmitted by fleas and rodents.
Plantar fasciitis commonly causes stabbing pain that usually occurs with your first steps in the morning. Learn about causes, treatments, prevention.
Learn about the causes, treatment and prevention of these hard, sometimes painful growths that appear on the heels or balls of the feet.
Pleurisy is a condition in which the tissues that line the lungs and chest cavity (pleura) become inflamed, causing sharp chest pain that worsens during breathing.
Pneumonia — Learn about the symptoms, causes and treatment of this serious lung infection.
Pneumonitis is a general term for lung inflammation. It can cause difficulty breathing and is often accompanied by a cough.
A collapsed lung occurs when air leaks into the space between your lung and chest wall. This air pushes on the outside of your lung and makes it collapse.
Poison ivy rash — Comprehensive overview covers symptoms and treatment of this itchy skin rash.
Learn more about this contagious viral illness that in its most severe form causes nerve injury leading to paralysis, difficulty breathing and sometimes death.
Learn how treatments and lifestyle changes might help reduce damage to your kidneys from polycystic kidney.
Polycystic ovaries, hormone imbalance and irregular periods are telltale signs and symptoms of PCOS. Find out about PCOS treatments.
Polycythemia vera — Learn more about the signs, symptoms, diagnosis, and treatment of this slow-growing blood cancer that mainly affects people over 60.
Learn about symptoms, causes and treatment for polyhydramnios — excessive accumulation of amniotic fluid during pregnancy.
Learn more about the symptoms and treatments for this sun-induced skin rash that usually appears in spring or summer, and also after using tanning beds.
Older adults who suddenly develop muscle pain and stiffness, especially in the shoulders, might have polymyalgia rheumatica.
The muscle weakness associated with polymyositis can make it difficult to climb stairs or reach overhead. Breathing and swallowing also can be affected.
Poor color vision — Learn more about causes of colorblindness and how to diagnose whether you can't distinguish between certain shades of color.
Calf pain cramping your style during a workout? Know the signs and symptoms of popliteal artery entrapment syndrome.
Porphyria is a group of disorders that result from a buildup of porphyrin in your body, affecting your nervous system, skin and other organs.
Find out what to do when symptoms like headache, fatigue and dizziness last long after the injury that caused the concussion.
Post-polio syndrome — Comprehensive overview covers symptoms, causes, treatment of the late effects of polio.
Post-traumatic stress disorder (PTSD) is a mental health condition triggered by a terrifying event, causing flashbacks, nightmares and severe anxiety.
Learn about diagnosis and treatment for posterior cortical atrophy — a rare neurological syndrome that affects vision and coordination.
Posterior cruciate ligament (PCL) injury — Comprehensive overview covers knee symptoms, causes, treatment and prevention.
Learn about symptoms and possible treatments for this pelvic floor disorder where the rectum presses against weak tissues, bulging into the vagina.
This complication of shingles can cause pain, itching and numbness long after the shingles rash clears. Treatments can ease symptoms.
Learn the risk factors and symptoms of depression in new mothers, as well as effective treatment that can help you manage symptoms and bond with your baby.
Preeclampsia is a condition normally associated with pregnancy, but it can occur after delivery too. Untreated, it can lead to serious complications.
Learn about the definition, symptoms and treatment for this postpartum condition affecting the thyroid.
Prader-Willi syndrome is a rare genetic disorder that results in physical, mental and behavioral problems, including a constant sense of hunger.
Read about the signs and symptoms, causes, and risk factors that may cause a child's body to begin changing into an adult's body too soon.
Prediabetes — Comprehensive overview covers symptoms, risk factors, testing and prevention of this type 2 diabetes precursor.
Sudden weight gain and swelling, along with high blood pressure and protein in the urine, could be signs of preeclampsia. Learn what to watch for.
Having a preemie can be overwhelming. Here's what you need to know about your baby's care and the possible complications of a premature birth.
Understand what causes premature ejaculation, as well as how to treat it and prevent it.
Premature ovarian failure (POF) treatments include estrogen therapy for menopause symptoms and IVF with donor eggs for women who want to become pregnant.
Premature ventricular contractions (PVCs) are extra heartbeats that disrupt your regular heart rhythm. PVCs are common.
Mood swings, cramps and irritability are just a few telltale clues that you're getting your period. Learn what you can do for PMS symptom relief.
Have you noticed — yet — having to hold books at arm's length to read them? Find out what options are available when it happens.
Using a prescription medication in a way not intended by the doctor can lead to drug abuse. Learn about risk factors and treatment for drug misuse.
Preterm labor can affect any pregnancy. Understand the risk factors, signs and symptoms, and how early labor is treated.
Understand the symptoms, possible causes and treatment of prolonged erection of the penis, including when to seek emergency care.
Primary aldosteronism (al-DOS-tuh-ro-niz-um) is a type of hormonal disorder that leads to high blood pressure.
Primary biliary cholangitis (PBC) is a type of liver disease that damages the bile ducts. Early treatment may help prevent liver failure.
Frequent infections could mean you have an immune-system disorder. The conditions in this category are usually caused by genetic changes.
This motor neuron disease causes weakness, primarily in the muscles used to control the legs, arms and tongue.
Find out more about this type of dementia that affects the speech and language areas of the brain.
Primary sclerosing cholangitis, a rare, chronic and potentially serious bile duct disease, is curable with liver transplant.
Proctitis means inflammation of the rectal lining. This condition is often a treatment side effect or part of a more generalized disease.
Progeria is an extremely rare, progressive genetic disorder that causes children to age rapidly, beginning in their first two years of life.
Progressive supranuclear palsy — Comprehensive overview covers symptoms and self-care of this Parkinson's disease-like condition.
Learn about the symptoms, causes and treatment of this pituitary gland tumor.
Learn about detection, diagnostic approaches, treatment options and advances for prostate cancer, including robotic prostatectomy and current research.
Prostatitis — Comprehensive overview covers causes, symptoms and treatment of the swelling and inflammation of the prostate gland.
Pseudobulbar affect — Overview covers symptoms, treatment of this neurological condition that's characterized by uncontrollable laughing and crying.
Pseudocholinesterase deficiency (PD) — Comprehensive overview covers signs, symptoms and treatments for this drug sensitivity.
Pseudogout — Comprehensive overview covers symptoms, treatment, prevention of this disease that mimics gout.
This inflammatory colon condition is usually caused by the bacterium C. difficile. The use of high-dose antibiotics may let these germs grow unchecked.
Headaches and vision loss can result from this increased pressure inside your brain that occurs with no obvious reason.
Learn about this very common skin condition that causes skin cells to build up and form scales and itchy dry patches. Self-care and treatment may help.
Psoriatic arthritis occurs in people who have a skin condition called psoriasis. Some people develop severe joint damage from this autoimmune disorder.
Pubic lice (crabs) are an itchy, but treatable, nuisance. Find out how to spot and treat this common sexually transmitted infection (STI).
Learn more about this life-threatening congenital heart condition that changes the way blood normally travels from the heart to the rest of the body.
Pulmonary atresia with intact ventricular septum is diagnosed at or shortly after birth, and may be treated with one or more procedures.
If your baby has pulmonary atresia with intact ventricular septum, a heart problem, doctors may treat it with one or more procedures.
Get more information about what causes this potentially life-threatening lung condition, and learn how to treat and prevent it.
Pulmonary embolism is often caused by blood clots that travel to the lungs from the legs. Prevention is aimed at stopping clots from forming in the legs.
Pulmonary fibrosis — Learn about the symptoms, causes and treatment of this serious lung disease that occurs when lung tissue becomes damaged and scarred.
Pulmonary hypertension — Comprehensive overview covers symptoms, risk factors and treatment of this lung condition.
Learn more about this condition in which the pulmonary valve between the heart and lungs doesn't open properly, causing restricted blood flow.
In this condition, a valve between an infant's stomach and small intestine fails to open enough for food to pass through. Surgery is the treatment.
Learn about the symptoms, treatment and risk factors of this skin condition with open sores, along with advice on how to cope with it.
Learn more about the symptoms, treatment and prevention of this often mild bacterial infection spread by animals.
REM sleep behavior disorder is a sleep disorder in which you physically and vocally act out vivid, often unpleasant dreams during REM sleep.
Rabies is a deadly virus most often spread to people through the bite of an infected animal.
Read about what happens when someone is exposed to high doses of radiation, and what you can do to prevent such exposure in an emergency.
Ramsay Hunt syndrome occurs when a shingles outbreak affects the facial nerve near one of your ears, potentially causing facial paralysis and hearing loss.
Cold temperatures or stress can cause parts of your body, mainly fingers and toes, to numb, chill and possibly turn colors if you have Raynaud's disease.
Reactive arthritis can cause inflammation in the eyes and urinary tract — in addition to your joints. Symptoms typically disappear within a year.
Reactive attachment disorder is when an infant or young child doesn't establish healthy attachments with parents or caregivers, often due to neglect.
Rectal cancer — Learn about Mayo Clinic’s long record of excellence and innovation in treating this challenging type of cancer.
An abnormal connection between the rectum and vagina allows gas or stool to pass into the vagina. Learn about fistula treatment and self-care.
Learn about symptoms that alert doctors to a breast cancer recurrence and strategies for treating cancer that comes back after initial treatment.
Renal artery stenosis — Comprehensive overview covers causes, diagnosis, treatment of narrowing of the arteries leading to the kidneys.
This common pain in the part of a limb that remains after an amputation has many causes and effective treatment options.
Respiratory syncytial virus infection is a common illness that affects the lungs. It can seem like a cold, but may be severe, especially in children. Know the symptoms and treatment.
Uncomfortable sensations in your legs can interrupt your sleep — making you drag through your day. These therapies calm the restlessness and improve sleep.
Eye floaters and reduced vision are signs of possible retinal detachment. Find out about causes and treatment for this eye emergency.
Find out more about the symptoms, diagnosis and treatment for the varied conditions that affect the retinas and vision. Learn when to contact a doctor.
Learn about the symptoms, causes and treatments for this eye cancer that occurs in young children.
Find out about this condition that allows the testicle to move between the scrotum and groin.
Retrograde ejaculation — Comprehensive overview covers symptoms, treatment of condition that can cause male infertility.
This rare genetic disorder affects the way the brain develops, causing a progressive inability to use muscles for eye and body movements and speech.
Learn more about the causes and treatment of Reye's syndrome, a rare but serious condition causing swelling in the liver and brain.
Rheumatic fever — Comprehensive overview covers symptoms, causes, treatment of this strep throat complication.
This chronic inflammatory disorder can affect more than just your joints. It can also damage the skin, eyes, lungs, heart and blood vessels.
Learn what can cause this bone-softening disease in children and how supplements may prevent or treat the condition.
Learn more on causes, symptoms, treatments of this easily spread fungal skin infection that itches and is related to athlete's foot.
Ringworm (scalp) — Comprehensive overview covers causes, symptoms and treatments of this fungal infection.
Recognize Rocky Mountain spotted fever early to get prompt and potentially lifesaving treatment.
Learn more about this common facial skin condition, including symptoms, triggers, good skin care and medications to treat it.
Learn about the symptoms, causes and treatment of this common childhood infection and rash caused by two strains of herpes virus.
This common shoulder disorder is often caused by repetitive overhead motions in jobs or sports. Extensive rotator cuff tears may require surgery.
Learn more about this common childhood condition that causes fever, vomiting, diarrhea and sometimes abdominal pain.
Learn more about the symptoms and prevention of this contagious viral infection best known for its distinctive red rash.
A ruptured eardrum is a hole or tear in your eardrum, the thin tissue that separates your ear canal from your middle ear.
A break in the surface of your spleen, usually from a forceful blow to your abdomen, can cause life-threatening internal bleeding.
Sacral dimple — Comprehensive overview covers complications, treatment of this indentation on the lower back.
Sacroiliitis — Comprehensive overview covers symptoms, causes, diagnosis, treatment of inflammation of the sacroiliac joints.
Learn about this rare type of tumor affecting the salivary glands and treatments such as surgery and radiation therapy.
Salmonella infection (salmonellosis) affects the intestinal tract. Learn more about the causes, treatment and prevention of this common bacterial disease.
This inflammatory disease results in growth of tiny granulomas in different parts of the body, including the lungs, eyes, skin and heart.
Learn about this cancer that forms in the bones and the connective tissue. Find out about symptoms, diagnosis, treatment and the many types of sarcoma.
Learn more about this infectious condition that causes intense itching, usually in areas where the skin folds, such as around joints.
Learn more about the symptoms, causes, complications and treatment of this strep-related bacterial infection.
Schizoaffective disorder includes schizophrenia symptoms, such as delusions or hallucinations, and mood disorder symptoms, such as depression or mania.
Schizoid personality disorder is an uncommon condition in which people consistently shy away from interaction with others and have a limited range of emotional expression.
Schizophrenia is a severe mental disorder that can result in hallucinations, delusions, and extremely disordered thinking and behavior.
Schizotypal personality disorder — Learn about symptoms, causes and treatment of this socially isolating disorder.
Learn about the diagnosis and treatment of this usually benign, slow-growing tumor that begins in peripheral nerve cells.
Sciatica — Comprehensive overview covers symptoms, treatment of this acute back, pelvic and leg pain.
This group of rare diseases involves the hardening and tightening of the skin and connective tissues. Some forms can affect internal organs.
This sideways curvature of the spine occurs most often during the growth spurt just before puberty. Treatment may include braces or surgery.
Learn more about symptoms, risk factors, treatment and prevention of this type of sting, which is painful but rarely life-threatening.
Scrotal masses have many underlying causes. Even painless scrotal masses should be evaluated promptly by a doctor.
Seasonal affective disorder (SAD) is a type of depression that's related to changes in seasons and begins and ends at about the same times every year.
Sebaceous carcinoma — Overview covers diagnosis and treatments, including Mohs surgery, for this rare skin cancer that often affects the eyelid.
Find out what you can do to treat this flaky skin condition that can cause scaly skin and stubborn, itchy dandruff.
Seborrheic keratosis — Comprehensive overview includes symptoms and treatments of this common, noncancerous skin growth common in older adults.
Learn more about secondary hypertension, including risk factors and treatments to help you stay healthy.
Learn about seizure types, what causes seizures, what happens during a seizure and what you can do if you see someone having a seizure.
Deliberately hurting your own body, such as cutting or burning, is a harmful way to cope with emotional pain, intense anger and frustration.
A separated shoulder is an injury to the ligaments that hold your collarbone to your shoulder blade. Learn about causes, symptoms and treatment options.
Intense or prolonged separation anxiety that interferes with school or other daily activities or includes panic attacks. Learn about treatment.
Learn more about the symptoms and treatment of sepsis, a serious infection-related illness.
Septic arthritis — Comprehensive overview covers symptoms and treatment of joint infections.
Serotonin syndrome occurs when drug interactions or overdose causes serotonin levels to rise to potentially dangerous levels.
Severe acute respiratory syndrome (SARS) is a contagious and sometimes fatal respiratory illness.
Sex headaches — Comprehensive overview covers causes, treatment of this variety of headache.
Learn about risk factors, symptoms, diagnosis, treatment and prevention of sexually transmitted infections (STIs), or sexually transmitted diseases (STDs).
Shaken baby syndrome is a severe brain injury caused by violently shaking a child. Know the symptoms and treatment.
Sheehan's syndrome — Comprehensive overview covers signs and symptoms, causes, treatment of this rare complication of postpartum hemorrhage.
It's possible to be allergic to some types of shellfish without reacting to other types. Learn more about this common food allergy.
Shigella infection covers symptoms, treatment and prevention of this diarrhea-causing illness.
Shin splints are common in runners, dancers and military recruits. Learn how modifying your exercise routine can help prevent shin splints from recurring.
Learn more about the symptoms, causes, treatment and vaccine prevention of this painful condition affecting the nerves.
Sick sinus syndrome is a group of heart rhythm problems in which the heart's natural pacemaker doesn't work properly.
Sickle cell anemia — Learn about the symptoms, causes, treatment of this inherited blood disorder that, in the United States, is more common among blacks.
Sinus headaches are often to blame for headache with facial pain — but that pain might actually be a migraine.
If you're bothered by dry eyes and mouth, talk to your doctor about whether you have the autoimmune condition Sjogren's syndrome.
Learn about skin cancer, including basal cell carcinoma, melanoma and squamous cell carcinoma. Find out about symptoms, treatments and ways to lower your risk.
Snoring loudly could be an indication of sleep apnea, a disorder in which breathing stops and starts repeatedly during sleep.
Sleep terrors (night terrors) are episodes of screaming, intense fear and flailing while still asleep.
Sleep-related eating disorder involves episodes of compulsive eating while sleepwalking during the night, with little or no memory of it in the morning.
Comprehensive overview covers causes, treatment and prevention of this usually harmless sleep disorder.
Small bowel cancer starts in the small intestine. Find out more about symptoms and treatments, including surgery, chemotherapy and targeted therapy.
Learn more about this condition also called a vaginal hernia that happens when the small bowel pushes down onto the top of the vagina.
Small vessel disease — Comprehensive overview covers symptoms and treatment of this heart condition.
Learn about the symptoms, causes and vaccine prevention of this contagious, disfiguring and sometimes fatal viral disease.
Is the sound of snoring disrupting sleep in your household? Find out causes and treatment options for this common problem.
Social anxiety disorder is when everyday interactions cause significant worry and self-consciousness because you fear being judged by others.
Learn about the symptoms of this type of cancer that forms in the back part of the mouth. Treatment options might include surgery, radiation and chemotherapy.
This rare type of cancer can begin in the muscles, fat, blood vessels, nerves, tendons and the lining of joints. Treatment usually includes surgery.
This rare type of tumor most often occurs near the lungs. Surgery is the preferred treatment. Radiation and chemotherapy may be needed in some instances.
This rare condition is often linked to chronic constipation, along with one or more open sores in the rectum.
Learn about symptoms, causes and treatment for this disorder, which is linked with major emotional distress and impairment.
Find out what causes this common affliction, when to see a doctor and what you can do to get relief from a sore throat.
Soy allergy is a common food allergy that generally begins in infancy and often is outgrown in childhood.
Specific phobias are an overwhelming and unreasonable fear of objects or situations that pose little real danger but provoke anxiety and avoidance.
Learn more about this noncancerous testicular disorder, which might require surgery if it's causing discomfort.
Learn more about prevention, symptoms, complications and treatment of spider bites, which are usually harmless.
Fetal surgery during pregnancy may improve outcomes for babies with myelomeningocele, a severe form of spina bifida. Learn the latest treatment options.
Learn more about how this rare blood vessel disorder can affect the spinal cord.
Learn more about what happens after your spinal cord has been damaged.
Spinal cord tumors can cause serious problems such as pain and paralysis. Find out how more about management and treatment.
Spinal headaches — Comprehensive overview covers causes, treatment of this often severe headache.
Learn about this common back problem caused by narrowing of space in the spine. Lifestyle changes, physical therapy and medication can decrease the pain.
Spontaneous coronary artery dissection (SCAD) — Learn more about this condition that causes a tear in a blood vessel in the heart.
Sprained ankle — Injury to a ligament of the ankle can usually be treated with at-home care and appropriate exercises to get you back on your feet.
A sprain is a stretching or tearing of ligaments — the tough bands of tissue that connect two bones together in your joints. Ice and elevation can help.
Squamous cell carcinoma is a common skin cancer that usually looks like a red bump or a scaly sore. Learn about symptoms and explore treatment options.
Find out how doctors diagnose and treat advanced prostate cancer that has spread to the lymph nodes or other parts of the body.
Staph infections — Comprehensive overview covers symptoms, causes, treatment, prevention of these potentially lethal infections.
This rare disorder of the skin and mucous membranes is a severe reaction to medication or infection that causes the top layer of skin to die and shed.
Stickler syndrome — Learn more about this complex congenital disorder, which can weaken connective tissue and harm the heart, eyes, joints and ears.
Stomach cancer rates have fallen, but cancer at the junction of the stomach and esophagus has become more common. Learn more.
Stomach polyps — Comprehensive overview covers symptoms and treatment for stomach polyps.
Learn more about the symptoms, causes and treatment of this throat bacterial infection in children and adults.
Stress fractures are tiny cracks in bones, usually caused by overuse or osteoporosis. Learn more about how to prevent and treat these painful injuries.
Coughing, laughing, running — all can lead to accidental urine leakage if you have stress incontinence. Learn about treatment options and self-care.
Stretch marks — Comprehensive overview covers causes, symptoms and treatments.
Promptly spotting stroke symptoms leads to faster treatment and less damage to the brain.
Stuttering, sometimes called stammering, is a speech disorder that involves frequent and significant problems with normal fluency and flow of speech.
Sty — Comprehensive overview covers symptoms, causes, treatment of this irritating eyelid infection.
Find out more about diagnosis and treatment options for this bleeding in the brain.
Subconjunctival hemorrhage is a broken blood vessel in the eye — Learn more about this common, harmless condition that clears up without treatment.
A sudden loss of heart function is a medical emergency. Fast, appropriate care might keep it from being deadly.
Fluffy blankets and tummy sleeping increases SIDS risk for babies. Learn about other SIDS risks and how you can create a safe sleeping space for your baby.
Suicide can be prevented. Learn suicide warning signs and how to reach out for immediate help and professional treatment.
Learn more about the causes, symptoms and treatment of this itchy, red rash that is an allergic reaction to sunlight.
Long hours in the sun and unprotected skin mean one thing: sunburn. Here's what you can do for sunburn relief.
Supraventricular tachycardia (SVT) is an abnormally fast heartbeat that originates above the ventricles in the atria or AV node. For many people, treatment and lifestyle changes can control or eliminate this heart rhythm problem.
Sweating and body odor — Learn more about the causes, treatment and self-care of this normal skin condition. Unusual changes may mean a medical problem.
Sweet's syndrome — Comprehensive overview covers symptoms, causes, treatment of this painful skin condition.
The moist environment created by water remaining in your ear after swimming can cause this infection in the outer ear canal.
Swimmer's itch — Learn more about the symptoms, treatment and prevention of this itchy rash that usually affects people swimming in freshwater lakes.
Swine flu may refer to influenza in pigs or to an infection in humans caused by the H1N1v or H3N2v viruses. Learn more about how to prevent and treat flu.
Swollen knee — Comprehensive overview covers symptoms, causes, treatment of water on the knee.
Swollen lymph nodes — Comprehensive overview covers symptoms and treatment of this common medical complaint usually caused by infection or illness.
Synovial sarcoma is a rare type of cancer that tends to arise near large joints, particularly the knee, in young adults. The main treatment is surgery.
Syphilis, a sexually transmitted infection, first appears as painless sores on your genitals, rectum or mouth. Early diagnosis is important.
Syringomyelia occurs when fluid accumulates in the spinal cord. It can eventually damage the spinal cord and cause symptoms like pain and muscle weakness.
Treatment options for pain in your jaw joint and in the muscles that control jaw movement can include pain management, medical therapies and surgery.
Tachycardia — Comprehensive overview covers symptoms, diagnosis and treatment of a rapid heartbeat.
This rare disease damages the aorta — the large artery that carries blood from your heart to the rest of your body. Medications can prevent complications.
This infection may have a major "ick" factor, but it usually only causes a mild intestinal illness.
Tay-Sachs disease is a rare, inherited condition affecting the nerve cells. Find out more about symptoms, diagnosis and management of this disorder.
This serious mental health problem affects how your teenager thinks, feels and behaves, and can cause emotional, functional and physical problems.
These seizures begin in the temporal lobes of the brain, and can trigger a variety of symptoms, such as odd feelings, fear and unresponsiveness.
Repetitive activities and weekend warrior exercise can aggravate tendons, causing pain and swelling.
Tennis elbow — Painful condition is caused by repetitive motions of the wrist and arm. Non-athletes are also affected. Learn how to prevent and treat it.
Tension headache — Comprehensive overview covers symptoms, causes, treatment and prevention of this common type of headache often associated with stress.
Mayo Clinic testicular cancer care reflects deep expertise across all the disciplines that your needs demand, working as an integrated team.
Sudden, severe pain in the scrotum could be testicular torsion. Learn about symptoms and treatment for this health emergency.
Learn more about the symptoms, causes and vaccines used to prevent tetanus, a bacterial infection commonly known as "lockjaw."
Learn more about a rare condition caused by a combination of four heart defects that are present at birth (congenital).
Thalassemia — Learn more about symptoms, causes, treatment of this inherited blood disorder that usually shows up before 2 years of age.
Learn about the diagnosis and treatment of this serious condition in which the upper part of the blood vessel that feeds blood to the body is weakened.
Thoracic outlet syndrome — Comprehensive overview covers symptoms, treatment of this nerve and circulatory condition.
Learn more about this type of cancer that affects your throat (pharynx), voice box (larynx) or tonsils.
Thrombocytopenia — Comprehensive overview covers symptoms, causes, treatment of a low platelet count.
This condition occurs when your body produces too many platelets, the cells that help blood clot. Thrombocytosis can cause clotting or bleeding problems.
Thrombophlebitis — Comprehensive overview covers symptoms, risk factors, treatment of this vein condition.
This common condition can cause pain and mobility issues, making simple tasks difficult. Treatment may include medications, splints and sometimes surgery.
Thunderclap headaches, which are sudden and severe, can warn of a life-threatening condition — so seek immediate medical attention.
Comprehensive overview covers thyroid cancer diagnosis and treatment, including thyroid surgery, radioactive iodine and thyroid hormone therapy.
Thyroid nodules — Comprehensive overview covers symptoms, causes, treatment of lumps in the thyroid gland.
Learn about the symptoms, causes, treatments of this common skin infection that usually responds to treatment.
This comprehensive overview covers symptoms, causes, and treatment of phantom ear sounds.
Walking on toes or the balls of the feet is fairly common in children who are learning to walk. Most children outgrow it.
With tongue-tie (ankyloglossia), a band of tissue (frenulum) tethers the tongue, restricting the range of motion. Learn about symptoms and treatment.
Tonsillitis — Comprehensive overview covers symptoms, treatment for this common cause of sore throat in children.
A bacterial infection at the tip of the tooth root usually occurs from an untreated dental cavity, an injury or prior dental work.
Torn meniscus — Comprehensive overview covers causes, symptoms and treatment of this common knee injury.
Learn more about this condition in which the blood vessels that lead from the lungs (pulmonary veins) attach to the wrong places in the heart.
The repetitive movements and sounds called tics that characterize Tourette syndrome can affect daily life — but there are ways to manage them.
Find out about symptoms and treatment for toxic hepatitis — liver inflammation caused by exposure to certain substances, such as alcohol or medications.
Toxic shock syndrome is a rare, potentially fatal complication of certain types of bacterial infections. Learn about symptoms, risk factors and treatment.
Read about symptoms, causes, treatment and tips for prevention of this parasitic infection that for some people, can cause severe complications.
Trachoma is the leading preventable cause of blindness worldwide. Find out about symptoms, treatment and prevention of this serious eye disease.
When your memory suddenly disappears, it can be frightening — but transient global amnesia is typically temporary and harmless.
Transient ischemic attack (TIA) — Comprehensive overview covers symptoms, causes, treatment of this neurological condition, often called a ministroke.
Transposition of the great arteries is a heart defect that requires surgery to correct. Learn about symptoms and treatment of this rare condition.
Transverse myelitis – learn more about the signs, symptoms and treatment of this neurological disorder that affects the spinal cord.
If a head injury causes a mild traumatic brain injury, long-term problems are rare. But, a severe injury can mean significant problems.
Travelers diarrhea — Know how to treat this international travel hazard when it strikes, and learn to avoid the contaminated food and water that cause it.
Learn about the symptoms, treatment and prevention of this type of roundworm infection.
You can reduce your risk of trichomoniasis — a sexually transmitted infection caused by a parasite — by using condoms when you have sex.
Trichotillomania (hair-pulling disorder) involves recurrent, irresistible urges to pull out hair from your body. Therapy may help reduce or stop urges.
Tricuspid atresia, a heart valve defect that's present at birth, obstructs blood flow from the heart to the lungs. Treatment involves multiple surgeries.
Learn about this heart condition that occurs if the heart's tricuspid valve doesn't shut properly. You may feel tired and have difficulty exercising.
Learn about this painful nerve condition that can jolt areas on the face with electric-shock-like pain.
Learn more about this painful condition that causes a finger to get stuck in a bent position, including how to treat it.
Females with this genetic disorder have three X chromosomes rather than the usual two, which may result in developmental delays and learning disabilities.
Learn more about this rare heart defect that makes it difficult for the heart to pump the right amount of blood to both the lungs and the body.
Learn about the symptoms, treatment and prevention of this common infectious disease.
Tuberous sclerosis is a rare genetic disorder that causes noncancerous (benign) tumors ? unexpected overgrowths of normal tissue ? in parts of the body.
Tularemia is an infection caused by bacteria that mainly affect wild animals. Learn about symptoms, treatment and prevention of this rare disease.
Turner syndrome affects only females as the result of a missing or partially missing X chromosome, causing a variety of medical and developmental problems.
Learn about the symptoms, causes, treatment of this chronic condition in which the pancreas produces little or no insulin.
Type 1 diabetes in children — Comprehensive overview covers diagnosis, treatment, complications of this insulin-dependent condition.
Learn more about this common condition, including what symptoms to watch for and ways to prevent or slow this often weight-related condition.
Type 2 diabetes in children — Comprehensive overview covers diagnosis, treatment, complications of this blood sugar condition.
Learn more about the symptoms, cause and treatment of this serious intestinal illness.
Ulcerative colitis, a severe inflammatory bowel disease, increases risk of colon cancer and may require surgery to remove part of the bowel.
Treatment is usually unnecessary for this common condition in babies. In adults, the condition is more likely to cause problems.
Learn about causes, complications and treatment of this condition in which one or both testicles aren't in their normal place within the scrotum.
Learn about this soft-celled cancer that forms in the extremities and retroperitoneum. Treatment options include surgery and radiation therapy.
Find out how doctors use minimally invasive surgery to treat this rare cancer that forms in the tubes that connect your kidneys to your bladder.
Understand what causes blockage of the tubes that carry urine from the kidneys to the bladder, tests you might need and how the condition can be treated.
Narrowing of the tube that carries urine from the body (urethra) can restrict urine flow and cause a variety of problems.
Read more about what causes the loss of bladder control as well as what treatments are available for this problem.
Urinary symptoms — such as blood in the urine and burning with urination — could result from a UTI. Learn about UTI causes, treatments and self-care.
Foods and medications can change the color of your urine. But a color change could be a sign of disease.
Learn about these common noncancerous growths and what to do if you experience symptoms such as heavy menstrual bleeding.
Uterine polyps are tissue growths inside the uterus that can cause abnormal uterine bleeding or infertility. Learn about uterine polyp tests and treatment.
Learn about symptoms and possible treatments, including surgical repair, for a weakened pelvic floor that causes the uterus to descend into the vagina.
Uveitis — Comprehensive overview covers causes, symptoms, risks, treatment of anterior and posterior uveitis.
Learn about this rare, congenital condition in which the vagina doesn't develop, and find out what treatments are available to reconstruct the vagina.
Read about this condition that causes vaginal and urinary symptoms, often after menopause. It's also called genitourinary syndrome of menopause.
Learn about vaginal cancer symptoms and diagnosis. Treatments for cancer of the vagina include surgery, radiation therapy and chemotherapy.
Vaginal discharge and itching can accompany yeast infection and other types of vaginitis. Recognize signs and symptoms and learn when to seek treatment.
Learn about symptoms and treatment for valley fever — an infection caused by fungi found in the soil of America's desert regions.
Find out how this condition involving the enlargement of veins in the scrotum can affect your sperm quality and production.
Read more about what causes those unsightly lines or cords under your skin, as well as what self-care steps you can take and what treatments are available.
Learn more about this stroke-related type of dementia that causes memory loss and reasoning problems. Prevention is possible, and good heart health is key.
Learn more about this condition in which malformations of the aortic arch encircle the trachea and esophagus and can press against them.
An inflammation of the blood vessels, vasculitis may thicken and weaken blood vessel walls. If blood flow is restricted, organ damage can occur.
Learn about what causes a brief loss of consciousness and when to see a doctor if this happens to you.
This heart rhythm problem can cause collapse within seconds. Learn how to recognize the signs and what actions to take to save a life.
Learn more about diagnosis and treatment of this common heart defect present at birth in which a hole occurs in the wall between the lower heart chambers.
Ventricular tachycardia, a rapid heart rate originating in the heart's lower chambers (ventricles), can be a life-threatening medical emergency.
Vertebral tumors grow in the bones of the spine, causing pain and weakening the spinal column. Read more about how they’re managed, and what to expect.
Vesicoureteral reflux is the abnormal flow of urine backward from the bladder. Usually found in children, it increases the risk of urinary tract infections.
This condition, often called stomach flu, is usually harmless, except for infants and people with immunosuppression. Symptoms can usually be managed.
Learn more about the symptoms, treatment and prevention of these sometimes deadly diseases.
Vitamin deficiency anemia — Comprehensive overview covers symptoms, causes, treatment of this blood disorder.
Learn more about this condition in which your skin loses pigment cells, resulting in very light or white patches on parts of your body.
Find out more about this condition caused by problems with the nerves that control your voice box.
Learn more about the causes of common voice disorders, such as laryngitis and granuloma, and how Mayo Clinic diagnoses and treats them.
Von Willebrand disease — Learn more about the symptoms, causes, diagnosis, treatment of this inherited bleeding disorder in which blood doesn't clot well.
Learn about this rare cancer that forms on the skin that surrounds the urethra and vagina. Treatments include surgery, radiation and chemotherapy.
If you have pain, burning or irritation in your vaginal area, talk to your doctor. You could have vulvodynia.
Learn about this rare type of white blood cell cancer. Treatments include chemotherapy, targeted therapy, immunotherapy and bone marrow transplant.
Learn more about the symptoms, treatment and prevention of this mosquito-borne illness.
Blurred vision or blind spots could be signs of wet macular degeneration. Find out about symptoms and treatment for this chronic eye disorder.
The causes, main symptoms and treatment of wheat allergy differ from those of celiac disease. But managing either condition involves avoiding wheat.
Whiplash is a common neck injury, often resulting from a car crash. But other trauma can cause it, too. Know the symptoms and how to treat it.
Learn more about the symptoms, causes and treatment of this rare primarily digestive infection.
Learn more about the symptoms, causes, treatment of this highly contagious, vaccine-preventable lung infection.
Advancements in the diagnosis and treatment of Wilms' tumor have greatly improved the outlook (prognosis) for children with this type of kidney cancer.
Wilson's disease, an inherited disorder, causes copper to accumulate in vital organs. It's treatable when diagnosed early.
Wolff-Parkinson-White (WPW) syndrome — Comprehensive overview covers diagnosis, treatment, complications of this heart condition involving an extra electrical pathway.
Wrist pain can be caused by many factors, ranging from sudden injuries to long-term problems such as arthritis. Treatment varies by cause.
Vaginal itching or burning could mean you have a yeast infection. Learn about other symptoms and effective treatments for this uncomfortable condition.
Understand the symptoms and how to protect yourself with a vaccine for this sometimes deadly mosquito-borne disease.
Learn about what causes these involuntary wrist spasms that often frustrate golfers.
Learn about the symptoms, causes, treatment and prevention of this mosquito-borne viral infection.