CausesBy Mayo Clinic staff
A wide range of factors — varying greatly in seriousness — can cause leg swelling.
Causes related to trapped fluids
Leg swelling caused by the buildup of fluids in leg tissues is known as peripheral edema. Several body systems help maintain the appropriate balance of fluids, including the circulatory system, the lymphatic system and the kidneys. A problem with any one of these systems may contribute to the buildup of fluids. Gravity can also contribute to the accumulation of fluids in your lower limbs, particularly with prolonged standing or sitting.
Leg swelling due to trapped fluids can be caused by such factors as:
- Acute kidney failure
- Chronic kidney failure
- Chronic venous insufficiency (problem with leg veins returning blood to the heart)
- Heart failure
- Hormone therapy
- Nephrotic syndrome
- Nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen (Advil, Motrin, others)
- Prescription medications, including some drugs for depression, diabetes and high blood pressure
- Prolonged sitting, such as during airline flights
- Prolonged standing
Causes related to inflammation
Leg swelling may also be caused by an immune system response that leads to inflammation in leg tissues. Inflammation may be a normal response to injury or disease, or it may be the result of an inflammatory disorder, such as rheumatoid arthritis. Leg swelling related to inflammation is usually associated with pain.
Factors that can contribute to inflammation in the leg include:
Causes shown here are commonly associated with this symptom. Work with your doctor or other health care professional for an accurate diagnosis.
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- Cho S, et al. Peripheral edema. American Journal of Medicine. 2002;113:580.
- O'Brien JG, et al. Treatment of edema. American Family Physician. 2005;71:2111.
- Treatment of pain and inflammation. The Merck Manuals: The Merck Manual for Healthcare Professionals. http://www.merck.com/mmpe/sec22/ch336/ch336e.html. Accessed March 1, 2009.
- Wilkinson JM (expert opinion). Mayo Clinic, Rochester, Minn. March 3, 2009.