Skip to main content


Medically reviewed by Last updated on Mar 11, 2022.

What is Lymphedema?

Harvard Health Publishing

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

Lymph normally does an important job for your body. It carries foreign material and bacteria away from your skin and body tissues, and it circulates infection-fighting cells that are part of your immune system.  

Lymph flows slowly through the network of vessels called your lymphatic system. Lymph flow stops at points along the way to be filtered through lymph nodes. Lymph nodes are small bean-shaped organs that are part of your immune system.  

Lymph is formed from the fluid that surrounds cells in the body. It makes its way into very small lymphatic vessels. After traveling through these small vessels, lymph drains into deeper, wider lymph channels that run through the body. Eventually, lymph fluid returns to the blood. 

Lymphedema occurs when there is inadequate lymph drainage from the body, usually from a blockage in a lymph channel. Lymphatic fluid builds up underneath the skin and causes swelling. Most commonly lymphedema affects the arms or legs. 

Swelling from lymphedema can look similar to the more common edema caused by leakage from tiny blood vessels under the skin.  

In most cases of lymphedema, the lymphatic system has been injured so that the flow of lymph is blocked either temporarily or permanently. This is called secondary lymphedema. Common causes include:  

  • Surgical damage — Surgical cuts and the removal of lymph nodes can interfere with normal lymph flow. Sometimes, lymphedema appears immediately after surgery and goes away quickly. In other cases, lymphedema develops from one month to 15 years after a surgical procedure. Lymphedema occurs quite often in women who have had multiple lymph nodes removed during surgery for breast cancer.  
  • An infection involving the lymphatic vessels —  An infection that involves the lymphatic vessels can be severe enough to cause lymphedema. In areas of the tropics and subtropics, such as South American, the Caribbean, Africa, Asia and the South Pacific, parasites are a common cause of lymphedema. Filariasis, a parasitic worm infection, blocks the lymph channels and causes swelling and thickening below the skin, usually in the legs.  
  • CancerLymphoma, a cancer that starts in the lymph nodes, or other types of cancer that spread to the lymph nodes may block lymph vessels.  
  • Radiation therapy for cancer — This treatment can cause scar tissue to develop and block the lymphatic vessels.  

When lymphedema occurs without any known injury or infection, it is called primary lymphedema. Doctors diagnose three types of primary lymphedema according to when symptoms first appear: 

  • At birth — Also known as congenital lymphedema. Risk is higher in female newborns. The legs are affected more often than the arms. Usually both legs are swollen. 
  • After birth but before age 36 — Usually, it is first noted during the early teenage years. This is the most common type of primary lymphedema. 
  • Age 36 and older — This is the rarest type of primary lymphedema. 

All three types of primary lymphedema are probably related to the abnormal development of lymph channels before birth. The difference is when in life they first cause swelling of the legs or arms. 


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. Swelling in the leg usually begins at the foot, and then moves up if it worsens to include 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  
  • 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. The doctor may ask if you have ever had a blood clot. If a child has lymphedema, the doctor will ask if anyone in your family had leg swelling starting at a young age. This may indicate an inherited disorder.  

Your doctor will examine the swollen area and press on the affected skin to look for a fingertip indentation (pitting). The skin will be indented in people with the much more common type of edema caused by leaky blood vessels. Pitting does not happen when you press on skin if you have lymphedema.  

Your doctor may measure the circumference of the affected arm or leg to determine how swollen it is compared to the other one. The doctor 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 the diagnosis is not clear or there is no obvious cause for your condition: 

  • A blood count can look for a high level of white cells, which means you might have an infection.  
  • An ultrasound can look for blood clots, which can cause an arm or leg to swell. 
  • A computed tomography (CT) scan looks for a mass or tumor that could be blocking lymph vessels in the swollen arm or leg.  

Expected Duration

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


After breast cancer or prostate cancer surgery, your doctor or physical therapist may advise that you do specific exercises once you have fully recovered from the surgery. Using your muscles can encourage the flow of lymph through small channels.  

After breast surgery, you are less likely to develop lymphedema if you can avoid having injections, intravenous (IV) lines, or blood drawn in the arm on the side of the surgery. Also, be sure to get prompt treatment if you think you may have a skin infection on the side of your surgery.  

Other ways to help decrease the risk of secondary lymphedema include: 

  • Avoid heavy lifting with the arm at risk 
  • Elevate your arm or leg(s) 
  • Don't put use a heating pad on the arm or leg at risk 
  • Avoid any constriction, such as a blood pressure cuff or tight clothing 
  • Wear a compression stocking 


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 socks with tight bands across the top. Avoid standing for long periods. 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. Your doctor may suggest that you follow a protein-rich, low-salt diet. 

For people with more severe lymphedema, doctors prescribe inflatable sleeves that can be worn around the arm or leg, called pneumatic compression devices. These sleeves are attached to a machine that alternately fills and deflates them with air, and they can be used at home to help reduce limb swelling. An alternative to air-filled sleeves is to wrap the limb with a non-elastic bandage, and adjust the bandage each time the swelling decreases.  

A very helpful treatment is a type of massage therapy called manual lymph drainage. Massage should not be done if you have cancer in the limb.  

Surgery may be an option for some people with lymphedema. Several different procedures are available. Some aim to restore lymphatic circulation. In other cases, the goal is to remove excess fat that has been deposited as a result of the lymphedema. 

People with lymphedema are more prone to infection in the affected arm or leg. If your doctor suspects you have an infection, you will need to take antibiotics by mouth or into a vein (intravenously).  

When To Call a Professional

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

You should call your doctor the same day if you have symptoms that could be from an infection: 

  • Fever, redness, warmth or increased pain in addition to swelling  
  • Open sores or areas of broken skin 


It isn't always easy to predict whether edema will last. Most of the time, treatments can improve lymphedema symptoms.

Additional Info

National Heart, Lung, and Blood Institute (NHLBI)

National Cancer Institute (NCI)

National Lymphedema Network

Office of Rare Diseases

Learn more about Lymphedema

Treatment options

Care guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.