Definition

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 common, easily identified and no reason for concern. Sometimes leg swelling can indicate a more serious disorder, such as heart disease or a blood clot.

Seek medical care right away if your legs swell for no apparent reason, especially if you have unexplained leg pain, difficulty breathing, chest pain or other warning signs of a blood clot in your lungs or a heart condition.

Causes

Many factors — varying greatly in severity — 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 venous circulation system, the lymphatic system or the kidneys.

Leg swelling isn't always a sign of a heart or circulation problem. You can have swelling due to fluid buildup simply from being overweight, being inactive, sitting or standing for a long time, or wearing tight stockings or jeans.

Factors related to fluid buildup include:

• Acute kidney failure
• Cardiomyopathy (problem with the heart muscle)
• Chemotherapy
• Chronic kidney disease
• Cirrhosis (scarring of the liver)
• Deep vein thrombosis (DVT) (DVT)
• Heart failure
• Hormone therapy
• Lymphedema (blockage in the lymph system)
• Nephrotic syndrome (damage to small filtering blood vessels in the kidneys)
• Obesity
• Pain relievers, such as ibuprofen (Advil, Motrin IB) or naproxen (Aleve)
• Pericarditis (inflammation of the tissue around the heart)
• Pregnancy
• Prescription medications, including some used for diabetes and high blood pressure
• Pulmonary hypertension
• 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 joints or tissues — either a normal response to injury or disease or due to rheumatoid arthritis or another inflammatory disorder. You'll usually feel pain with inflammatory disorders.

Conditions 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 ankle
• Broken foot
• Broken leg
• Burns
• Cellulitis (a skin infection)
• 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 can 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 cause.

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 might 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 acetaminophen (Tylenol, others) might ease pain associated with the swelling.