Definition of peripheral edema (leg swelling)
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.
Causes of peripheral edema (leg swelling)
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. You may also experience swelling due to fluid buildup after sitting or standing for a long time.
Factors related to fluid buildup include:
- Acute kidney failure
- Cardiomyopathy (disease of heart tissue)
- 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 or naproxen
- Pericarditis (swelling of the membrane surrounding 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 ankle/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 lasting more than a few minutes
- Difficulty breathing
- Fainting or dizziness
Also, seek immediate care if your leg swelling:
- Occurs for no apparent reason
- Is related to a physical injury, such as from a fall, a sports injury or a car accident
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:
- Put a pillow under your legs when lying down, which may lessen swelling related to the buildup of fluid.
- 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.