Lymphedema occurs when the lymph system is damaged or blocked. Fluid builds up in soft body tissues and causes swelling. It is a common problem that may be caused by cancer and cancer treatment. Lymphedema usually affects an arm or leg, but it can also affect other parts of the body. Lymphedema can cause long-term physical, psychological, and social problems for patients.
The anatomy of the lymph system includes the lymph vessels and lymph organs, including the lymph nodes, tonsils, thymus, spleen, and bone marrow. Lymph (clear fluid) and lymphocytes travel through the lymph vessels and into the lymph nodes where the lymphocytes destroy harmful substances. The lymph enters the blood through a large vein near the heart.