Heart murmurs are sounds — such as whooshing or swishing — made by turbulent blood in or near your heart. Your doctor can hear these sounds with a stethoscope. A normal heartbeat makes two sounds like "lubb-dupp" (sometimes described as "lub-DUP") when your heart valves are closing.
Heart murmurs can be present at birth (congenital) or develop later in life.
Heart murmurs can be harmless (innocent) or abnormal. An innocent heart murmur is not a sign of heart disease and doesn't need treatment. Abnormal heart murmurs require follow-up testing to determine the cause. Treatment is directed at the cause of your abnormal heart murmur.
If you have an innocent heart murmur, you likely won't have any other signs or symptoms.
An abnormal heart murmur may cause the following signs and symptoms, depending on the cause of the murmur:
- Skin that appears blue, especially on your fingertips and lips
- Swelling or sudden weight gain
- Shortness of breath
- Chronic cough
- Enlarged liver
- Enlarged neck veins
- In infants, poor appetite and failure to grow normally
- Heavy sweating with little or no activity
- Chest pain
When to see a doctor
Most heart murmurs aren't serious, but if you think you or your child has a heart murmur, make an appointment to see your family doctor. Your doctor can tell you if the heart murmur is innocent and doesn't require any further treatment or if an underlying heart problem needs to be further examined.
A heart murmur may happen:
- When the heart is filling with blood (diastolic murmur)
- When the heart is emptying (systolic murmur)
- Throughout the heartbeat (continuous murmur)
A heart murmur may be innocent or abnormal.
Innocent heart murmurs
A person with an innocent murmur has a normal heart. This type of heart murmur is common in newborns and children.
An innocent murmur can occur when blood flows more rapidly than normal through the heart. Conditions that may cause rapid blood flow through your heart, resulting in an innocent heart murmur, include:
- Physical activity or exercise
- Not having enough healthy red blood cells to carry adequate oxygen to your body tissues (anemia)
- Too much thyroid hormone in your body (hyperthyroidism)
- Phases of rapid growth, such as adolescence
Innocent heart murmurs may disappear over time, or they may last your entire life without ever causing further health problems.
Abnormal heart murmurs
In adults, abnormal murmurs are most often due to acquired heart valve problems. In children, abnormal murmurs are usually caused by structural problems of the heart (congenital heart defects).
Common congenital defects that cause heart murmurs include:
- Holes in the heart. Known as septal defects, holes in the heart may or may not be serious, depending on the size of the hole and its location.
- Cardiac shunts. Cardiac shunts occur when there's an abnormal blood flow between the heart chambers or blood vessels, which may lead to a heart murmur.
- Heart valve problems present from birth. Examples include valves that don't allow enough blood through them (stenosis) or those that don't close properly and leak (regurgitation).
In older children and adults, causes of abnormal heart murmurs include infections and conditions that damage the structures of the heart. For example:
- Valve calcification. This hardening or thickening of valves, as in mitral stenosis or aortic valve stenosis, can occur as you age. Valves may become narrowed (stenotic), making it harder for blood to flow through your heart, resulting in murmurs.
Endocarditis. This infection of the inner lining of your heart and valves typically occurs when bacteria or other germs from another part of your body, such as your mouth, spread through your bloodstream and get stuck in your heart.
Left untreated, endocarditis can damage or destroy your heart valves. This condition usually occurs in people who already have heart valve problems.
- Rheumatic fever. Although now rare in the United States, rheumatic fever is a serious condition that can occur when you don't receive prompt or complete treatment for a strep throat infection. It can permanently affect the heart valves and interfere with normal blood flow through your heart.
You have an increased risk of a heart murmur if someone in your family had a heart defect associated with the unusual sounds.
Many different medical conditions can increase your risk of heart murmurs, including:
- A weakened heart muscle (cardiomyopathy)
- An infection of the lining of the heart (endocarditis)
- Blood disorders marked by a high number of certain white cells, called eosinophils (hypereosinophilic syndrome)
- Certain autoimmune disorders, including lupus and rheumatoid arthritis
- Chemicals from a rare tumor in the lungs or gastrointestinal system that enter your bloodstream (carcinoid syndrome)
- Heart valve disease
- High blood pressure (hypertension)
- High blood pressure in the lungs (pulmonary hypertension)
- History of rheumatic fever
- Overactive thyroid (hyperthyroidism)
Having uncontrolled diabetes or a rubella infection during pregnancy increases your baby's risk of developing heart defects and a heart murmur. Use of certain medications, alcohol or drugs during pregnancy can lead to heart defects in a developing baby, which may cause a heart murmur.
While there's not much you can do to prevent a heart murmur, it is reassuring to know that heart murmurs are not a disease and are often harmless. For children, many murmurs go away on their own as children grow. For adults, murmurs may disappear as the underlying condition causing them improves.
Heart murmurs are usually detected when your doctor listens to your heart using a stethoscope during a physical exam.
To check whether the murmur is innocent or abnormal, your doctor will consider the following:
- How loud is it? This is rated on a scale from 1 to 6, with 6 being the loudest.
- Where in your heart is it? And can it be heard in your neck or back?
- What pitch is it? Is it high-, medium- or low-pitched?
- What affects the sound? Does exercising or changing body position affect the sound?
- When does it occur, and for how long? A murmur that happens when the heart is filling with blood (diastolic murmur) or throughout the heartbeat (continuous murmur) may signal a heart problem. Tests need to be done to find the cause. A murmur that occurs when the heart is emptying (systolic murmur) generally is an innocent heart murmur. Innocent heart murmurs aren't a sign of heart disease and don't require treatment.
Your doctor will also look for other signs and symptoms of heart problems and ask about your medical history and whether other family members have had heart murmurs or other heart conditions.
If your doctor thinks the heart murmur is abnormal, you or your child may need additional tests, including:
- Echocardiogram. This test is the main test used to determine the cause of a heart murmur. An echocardiogram uses ultrasound waves to create detailed images of your heart's structure and function. It can help identify abnormal heart valves, such as those that are hardened (calcified) or leaking, and can also detect most heart defects.
- Chest X-ray. A chest X-ray shows an image of your heart, lungs and blood vessels. It can reveal if your heart is enlarged, which may mean an underlying condition is causing your heart murmur.
- Electrocardiogram (ECG). In this noninvasive test, a technician will place probes on your chest that record the electrical impulses that make your heart beat. An ECG records these electrical signals and can help your doctor look for heart rhythm and structure problems.
Cardiac catheterization. In this test, a catheter is inserted into a vein or artery in your leg or arm until it reaches your heart. The pressures in your heart chambers can be measured, and dye can be injected.
The dye can be seen on an X-ray, which helps your doctor see the blood flow through your heart, blood vessels and valves to check for problems. This test is generally used when other tests have been inconclusive.
An innocent heart murmur generally doesn't require treatment because the heart is normal. If an innocent murmur is caused by an illness, such as fever or an overactive thyroid (hyperthyroidism), the murmur will go away once that condition is treated.
An abnormal heart murmur is closely monitored by your doctor over time. Treatment depends on the heart condition causing the murmur and may include medications or surgery.
The medication your doctor prescribes depends on the specific heart problem you have. Some medications your doctor might give you include:
- Blood thinners (anticoagulants). This type of medicine prevents blood clots from forming in your heart and causing a stroke. Your doctor may prescribe traditional anticoagulants, such as aspirin, warfarin (Jantoven) or clopidogrel (Plavix). Newer blood thinners, called direct-acting oral anticoagulants (DOACs), also may be prescribed. Examples include apixaban (Eliquis), rivaroxaban (Xarelto), dabigatran (Pradaxa) and others.
- Water pills (diuretics). Diuretics remove excess fluid from your body, which can help treat other conditions that might worsen a heart murmur, such as high blood pressure.
- Angiotensin-converting enzyme (ACE) inhibitors. ACE inhibitors lower your blood pressure. High blood pressure can worsen underlying conditions that cause heart murmurs.
- Statins. Statins help lower your cholesterol. Having high cholesterol seems to worsen some heart valve problems, including some heart murmurs.
- Beta blockers. These drugs lower your heart rate and blood pressure. They're used for some types of heart valve problems.
Doctors used to recommend that most people with abnormal heart murmurs take antibiotics before visiting the dentist or having surgery to prevent bacteria from getting into the lining of the heart (infective endocarditis).
Doctors no longer recommend antibiotics before procedures, except for people who have an artificial heart valve, history of a heart valve infection or a congenital heart defect that increases the risk of infective endocarditis.
Surgery may be needed to correct a damaged or leaky valve that causes a heart murmur. Depending on your heart condition, your doctor may recommend one of several heart valve treatment options.
To repair a valve, your doctor may recommend one of the following procedures:
- Balloon valvuloplasty. This procedure is performed to relieve a narrowed valve. During a balloon valvuloplasty, a small catheter containing an expandable balloon is threaded into your heart, placed into the valve and then expanded to help widen the narrowed valve.
- Annuloplasty. In this procedure, your surgeon tightens the tissue around the valve by implanting an artificial ring. This allows the leaflets to come together and close the abnormal opening through the valve.
- Repair of structural support. In this procedure, your surgeon replaces or shortens the cords that support the valves (chordae tendineae and papillary muscles) to repair the structural support. When the cords and muscles are the right length, the valve leaflet edges meet and eliminate the leak.
- Valve leaflet repair. In valve leaflet repair, your surgeon surgically separates, cuts or pleats a valve flap (leaflet).
In many cases, the valve has to be replaced. Options include:
- Open-heart surgery. This is the main treatment for severe valve stenosis. Your surgeon removes the narrowed valve and replaces it with a mechanical valve or a tissue valve. Mechanical valves are made from metal. They are durable, but carry the risk of blood clots forming. Tissue valves may come from a pig, cow or human deceased donor. They often eventually need replacement.
- Ross procedure. This type of heart valve replacement uses your own pulmonary valve (autograft). It's not often used due to the availability of less complex, yet effective, options.
Transcatheter aortic valve replacement (TAVR). This is a less invasive approach to replacing a heart valve. TAVR involves replacing the aortic valve with a prosthetic valve through an artery in your leg or in a small incision in your chest.
In some cases, a valve can be inserted through a catheter into a tissue replacement valve that needs to be replaced (valve-in-valve procedure).
TAVR is usually reserved for people with severe aortic valve stenosis who are at increased risk of complications from aortic valve surgery.
Preparing for an appointment
If you think you or your child has a heart murmur, make an appointment to see your family doctor. Although most heart murmurs are harmless, it's a good idea to rule out any underlying heart problems that could be serious.
Because appointments can be brief, and because there's often a lot to discuss, it's a good idea to be prepared for your appointment. Here's some information to help you get ready and know what to expect from your doctor.
What you can do
- Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there are any advance preparations. For example, if you're having a certain type of echocardiogram, you may need to fast for several hours before your appointment.
- Write down any symptoms you or your child is experiencing, including any that may seem unrelated to heart murmurs.
- Write down key personal information, including a family history of heart murmurs, heart rhythm problems, heart defects, coronary artery disease, genetic disorders, stroke, high blood pressure or diabetes, and any major stresses or recent life changes.
- Make a list of all medications, vitamins or supplements that you or your child is taking.
- Take a family member or friend along, if possible. Sometimes it can be difficult to remember all of the information provided to you during an appointment. Someone who comes along with you may remember something that you missed or forgot.
- Be prepared to discuss diet and exercise habits. If you or your child doesn't already follow a diet or exercise routine, be ready to talk to your doctor about any challenges you might face in getting started.
- Write down questions to ask your doctor.
Your time with your doctor is limited, so preparing a list of questions can help you make the most of your time together. For heart murmurs, some basic questions to ask your doctor include:
- What's the most likely cause of the heart murmur?
- What are other possible causes for the heart murmur?
- What kinds of tests are necessary?
- What's the best treatment or follow-up care?
- What are the alternatives to the primary approach that you're suggesting?
- How should health conditions other than the heart murmur be managed?
- Are there any dietary or exercise restrictions that I need to follow?
- Should I see a specialist?
- If surgery is necessary, which surgeon do you recommend?
- Is there a generic alternative to the medicine you're prescribing?
- Are there any brochures or other printed material that I can take home with me? What websites do you recommend visiting?
What to expect from your doctor
Your doctor is likely to ask you a number of questions. Being ready to answer them may reserve time to go over any points you want to spend more time on. Your doctor may ask:
- When did you or your child first have symptoms?
- Have the symptoms been continuous or occasional?
- How severe are the symptoms?
- What, if anything, seems to make your symptoms better?
- Does anything make the symptoms worse?
- Have you ever noticed a bluish discoloration of the skin?
- Do you have shortness of breath? When does this happen?
- Have you ever fainted?
- Have you had chest pain?
- Have you had swelling in your legs?
- How do you feel when you exercise?
- Have you ever used illicit drugs?
- Have you ever had rheumatic fever?
- Does anyone else in the family have a heart murmur or a heart valve problem?