Leg swelling can occur in any part of the legs, including the feet, ankles, calves and thighs. Leg swelling can result either from fluid buildup (fluid retention) or from inflammation in injured or diseased tissues or joints.
Many of the causes of leg swelling, such as an injury or prolonged standing or sitting, are easily identified. Sometimes leg swelling may be a sign of a more-serious disorder, such as heart disease or a blood clot.
Seek medical care right away when leg swelling occurs for no apparent reason or you also have difficulty breathing, chest pain or other warning signs of a blood clot in your lungs or a serious heart condition.
Many factors — varying greatly in seriousness — can cause leg swelling.
Leg swelling related to fluid buildup
Leg swelling caused by the retention of fluid in leg tissues is known as peripheral edema. It can be caused by a problem with the circulatory system, the lymphatic system or the kidneys.
Leg swelling isn't always a sign of a heart or circulation problem. You may often experience swelling due to fluid buildup from being overweight, being inactive, after sitting or standing for a long time, or wearing tight stockings.
Factors related to fluid buildup include:
- Acute kidney failure
- Cardiomyopathy (problem with the heart muscle)
- Chronic kidney disease
- Cirrhosis (scarring of the liver)
- Deep vein thrombosis (DVT)
- Heart failure
- Hormone therapy
- Lymphedema (blockage in the lymph system)
- Nephrotic syndrome (damage to small filtering blood vessels in the kidneys)
- Pain relievers, such as ibuprofen (Advil, Motrin IB) or naproxen (Aleve)
- Pericarditis (inflammation of the tissue around the heart)
- Prescription medications, including some used for diabetes and high blood pressure
- Sitting for a long time, such as during airline flights
- Standing for a long time
- Thrombophlebitis (a blood clot that usually occurs in the leg)
- Venous insufficiency, chronic (leg veins with a problem returning blood to the heart)
Leg swelling related to inflammation
Leg swelling can also be caused by inflammation in leg tissues. Inflammation may be a normal response to injury or disease, or it may be due to rheumatoid arthritis or another inflammatory disorder. You will usually feel some pain with inflammation.
Factors that can contribute to inflammation in the leg include:
- Achilles tendon rupture
- ACL injury (tearing of the anterior cruciate ligament in your knee)
- Baker's cyst
- Broken foot
- Broken leg
- Cellulitis (a skin infection)
- Gout (arthritis related to excess uric acid)
- Infection or wound in the leg
- Knee bursitis (inflammation of fluid-filled sacs in the knee joint)
- Osteoarthritis (disease causing the breakdown of joints)
- Rheumatoid arthritis (inflammatory joint disease)
- Sprained ankle
When to see a doctor
Seek emergency medical care if you have leg swelling and any of the following signs or symptoms, which may indicate a blood clot in your lungs or a serious heart condition:
- Chest pain
- Difficulty breathing
- Shortness of breath with exertion or lying flat in bed
- Fainting or dizziness
- Coughing blood
Also, seek immediate care if your leg swelling:
- Occurs suddenly and for no apparent reason
- Is related to a physical injury, such as from a fall, a sports injury or a car accident
- Occurs in one leg and is painful, or is accompanied by cool, pale skin
Schedule a doctor's visit
Nonemergency problems related to leg swelling still need prompt care. Leg swelling that is the side effect of a drug can look just like leg swelling caused by a kidney disorder. Make an appointment as soon as possible so that your doctor can diagnose the underlying problem.
Before your appointment, consider the following tips:
- Restrict the amount of salt in your diet.
- Put a pillow under your legs when lying down, which may lessen swelling related to the buildup of fluid.
- Wear elastic compression stockings, but avoid stockings that are tight around the top (if you can see the indentation from the elastic, they may be too tight).
- If you need to stand or sit for long periods, give yourself frequent breaks and move around, unless the movement causes pain.
- Don't stop taking a prescription medication without talking to your doctor, even if you suspect it may be causing leg swelling.
- Over-the-counter (nonprescription) pain medication may lessen painful swelling.