What Is It?

Lymphedema is a buildup of a fluid called lymph in the tissues under your skin. Lymph builds up when something blocks its normal flow. This causes swelling, most commonly in an arm or leg.

Lymph carries away many of the infection-fighting cells, foreign material, and bacteria from your skin and body tissues through the network of vessels in the lymphatic system. The smallest lymphatic vessels near the skin drain lymph into deeper, wider lymph channels that run through the body. Eventually, the lymph fluid is returned to the blood.

In most cases of lymphedema, some outside factor injures the lymphatic system and blocks the flow of lymph either temporarily or permanently. Common causes include:

  • Surgical damage — Surgical cuts and removal of lymph nodes (bean-shaped organs along the lymph channels) can interfere with normal lymph flow. Sometimes, this type of lymphedema appears immediately after surgery and goes away quickly. In other cases, lymphedema develops later, from one month to 15 years after a surgical procedure. Lymphedema is most commonly seen in breast cancer patients who have had surgery. It develops in up to 25 percent of those who have a breast removed (mastectomy) along with lymph nodes under the arm. The risk doubles for those who also receive radiation treatments to the underarm area. Lymphedema also may occur after surgery for prostate or testicular cancer, melanoma and cancer in the lower abdomen.

  • An infection involving the lymphatic vessels — Rarely, a bacterial infection (lymphangitis) can be severe enough to cause lymphedema. However, in some parts of the world, parasites commonly cause lymphedema. Filariasis, a parasitic worm infection, blocks the lymph channels and causes swelling and thickening below the skin, usually in the legs. Filariasis is more common in areas of the tropics and subtropics in South America, the Caribbean, Africa, Asia and the South Pacific. Filariasis rarely is seen in the United States, except in people who emigrated from these regions of the world.

  • Cancer — Cancer that starts in the lymph nodes (lymphoma) or spreads to the lymph nodes occasionally blocks lymph vessels.

  • Radiation therapy for cancer — This treatment can cause scar tissue to develop and block the lymphatic vessels.

In a rare form of lymphedema that is present at birth, the lymphatic vessels are absent or do not function properly. Lymphedema that results from this abnormality is called primary lymphedema. Three types of primary lymphedema are diagnosed according to when symptoms first appear: at birth, at the time of puberty, or after age 35. Some types are inherited and linked to genetic abnormalities.


Lymphedema causes swelling with a feeling of heaviness, tightness or fullness, usually in an arm or leg. In most cases, only one arm or leg is affected. If the leg is involved, swelling usually begins at the foot, then progresses upward toward the ankle, calf and knee. Additional symptoms can include:

  • A dull ache in the affected limb
  • A feeling of tightness in the skin of the affected limb
  • Difficulty moving a limb or bending at a joint because of swelling and skin tightness
  • Pitting — small indentations left on the skin after you press on the swollen area
  • Shoes, rings or watches that suddenly feel too tight

Lymphedema can make it easier to develop a skin infection. Signs of infection include fever, pain, heat and redness. If lymphedema becomes chronic (long-lasting), the skin in the affected area often becomes thickened and hard.


Your doctor will ask you whether you have had any surgery, radiation treatments, or infections in the affected area. He or she also may ask if you have ever had a blood clot. If a child has lymphedema, the doctor will ask about a family history of leg swelling starting at a young age, which may indicate an inherited disorder.

Your doctor will exam the swollen area, and will gently press his or her finger on your affected skin and watch for a fingertip indentation (pitting). Your doctor also may measure the circumference of the affected arm or leg to determine how swollen it is compared to the other one. He or she will look for signs of infection, including fever, redness, warmth and tenderness.

Usually, no specific testing is necessary to diagnose lymphedema. But tests may be ordered if there is no obvious cause for your condition:

  • A blood count can look for a high level of white cells, which would suggest you may have an infection.

  • An ultrasound may be ordered to look for blood clots, which also can cause swelling of an arm of leg.

  • A computed tomography (CT) scan looks for a mass or tumor that could be blocking lymph vessels in the swollen arm or leg.

  • Lymphoscintigraphy and lymphangiography are more specialized tests that can identify the blocked area of lymph flow and can detect any lymph vessel abnormalities.

Expected Duration

How long lymphedema lasts depends on its cause. For example, if lymphedema develops immediately after surgery, it can clear up within one week as the swelling is reduced and the affected arm or leg is elevated to allow better drainage. However, if surgery or radiation therapy has produced long-term damage to the lymphatic system, lymphedema can become a long-term or recurring problem.


Most cases of lymphedema cannot be prevented. After breast cancer or prostate cancer surgery, your doctor or physical therapist may advise specific exercises to help decrease the amount of lymphedema. Wearing a compression stocking during the day can help to prevent leg swelling.


The basic treatment for lymphedema includes:

  • Elevating the affected limb
  • Doing exercises to help reduce swelling
  • Keeping the affected limb clean and dry and periodically applying lubricating lotions

If lymphedema affects your legs, avoid wearing stockings or socks with tight bands and avoid standing for long periods of time. If you work on your feet or at a desk all day, your doctor may prescribe special compression stockings for you to wear throughout the day. He or she also may suggest that you follow a protein-rich, low-salt diet and that you lose weight if you are obese.

For some people, doctors prescribe pneumatic compression devices to be used at home to help reduce limb swelling. Others recommend a special type of massage therapy called manual lymph drainage. People with lymphedema are more prone to infection in the affected arm or leg. If your doctor suspects you have an infection, he or she will prescribe antibiotics given orally (by mouth) or intravenously (into a vein).

When To Call A Professional

Make an appointment with your doctor if you develop symptoms of lymphedema in an arm or leg.

Call your doctor to be seen more urgently:

  • If you develop a fever, redness or warmth in addition to the swelling, so the doctor can rule out an infection
  • If you have lymphedema or you have had a mastectomy, lower abdominal surgery, or radiation treatments in the past, and the affected limb becomes, red, painful or hot, or if it develops open sores or areas of broken skin


The prognosis varies and is not always predictable. But even persistent lymphedema can be controlled.

Johns Hopkins patient information

Last revised:

Diseases and Conditions Center

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All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.