Secondary lymphedema is caused by injury or scarring to the lymph vessels or removal of the lymph nodes. It most commonly occurs as a result of surgery or radiation to the lymphatics. Such treatments are commonly given for cancers of the breast, uterus, bladder, ovary, prostate, testicles and for malignant melanomas and lymphomas.

Secondary lymphedema may also result from a trauma, a crush injury, hip or knee surgery, amputations, blood clots, vein grafts from cardiac surgery, chronic infections, or longstanding circulatory problems such as chronic venous insufficiency or diabetes.

It is estimated that there are over two million cases of secondary lymphedema in the U.S., most the result of breast cancer treatment. Estimates place the incidence of lymphedema at 20%-25% following removal of lymph nodes for treatment of breast cancer. Radiation increases the risk of developing lymphedema by about 25%.