Lymphedema is swelling due to excess lymph fluid. In cancer patients, it may occur in an area where lymph nodes were surgically removed or treated with radiation therapy. In other cases, infection or the cancer itself may trigger the condition. Lymphedema most often develops in an arm or leg and can be progressive.

The lymphatic system is an important part of the immune defense system. It produces and stores some of the cells needed by the body to fight infections and diseases, such as cancer. The lymphatic system also extracts lymph fluids from tissues and returns it to the blood stream. Lymph fluid consists of white blood cells, plasma and other substances. The lymphatic system includes:

• Lymph nodes (small, bean-shaped organs that produce immune cells and filter bacteria).
  
  
• Lymph vessels (tubes or canals that collect excess lymph from the tissues and carry it back to the blood).

When the lymphatic system is obstructed, the excess lymph remains in the body tissues and causes swelling. Although lymphedema cannot be cured, he condition often can be controlled.

Lymphedema may be categorized as primary or secondary. Primary lymphedema is a rare inherited condition in which the lymph nodes or lymph vessels are missing or are not working properly. Secondary lymphedema is more common. It can develop as a result of cancer, infection or scar tissue from radiation therapy or surgical removal of lymph nodes. Surgical removal of lymph nodes or lymph vessels makes it harder for lymph fluid to flow to other parts of the body. This can cause the fluid to build up, resulting in swelling. Scar tissue from lymph node removal or radiation therapy can also cause blockage of the lymphatic system, thereby increasing the risk for lymphedema.

While most patients who have been treated for cancer will not develop lymphedema, many others will develop this condition. It can occur after surgery or radiation therapy for any type of cancer, but is most common in patients treated for breast cancer. It also may develop with prostate cancer, pelvic area cancers, lymphoma and melanoma. According to the American Cancer Society (ACS), approximately 10 to 30 percent of women and 10 to 12 percent of men who have underarm (axillary) lymph nodes removed develop lymphedema.

Depending on the type of lymphedema, it can develop a few days or many years after surgery or cancer treatment. Symptoms include redness, swelling and sensations of heat in the affected area. If patients notice signs or symptoms of lymphedema for one to two weeks, they should notify their physician. The earlier the condition is diagnosed the earlier treatment may begin. Lymphedema is usually treated with physical methods, such as massage or physical therapy, as well as medication.

Although experts do not understand what makes some patients more likely to develop lymphedema than others, there are certain preventative methods that may reduce a person’s risk. These include avoiding infections, burns and injuries to the affected area, muscle strain and avoiding constriction of the area.

Patients with lymphedema often suffer emotional and psychological problems because the disorder is disfiguring, and in some cases painful and disabling. Individual counseling and support groups are available to patients suffering from these psychological problems.