The lymphatic system is part of the circulatory (blood) system and plays an important role in immunity. It also collects fluid from the tissue spaces and transports it for eventual return to the circulatory system. If the transport function of the lymphatic system is reduced, then swelling may occur in that region of the body. This specific type of swelling is known as lymphedema.
Lymphedema results from damage or impairment of the lymphatic system. People who have or have had cancer may be at risk for developing lymphedema because some of the treatments for cancer or cancer itself may impair the lymphatic system. For example, surgeries that remove lymph nodes, radiation therapy, and some tumours may lead to a reduction in the carrying or transport capacity of the lymphatic system. Lymphedema typically does not cause generalized swelling but instead shows up only in the region that may have been damaged. For example, somebody who had an axillary lymph node dissection for treatment of breast cancer may go on to develop lymphedema in the affected arm, hand or on the lateral trunk. Typically, we think of lymphedema affecting a limb—an arm or leg—but depending on where the lymphatic damage occurs, it can produce facial, genital or trunk swelling. In addition to visible swelling, many survivors also report other symptoms of lymphedema, including a feeling of heaviness, pain, tightness, aching and impaired function of the involved limb.
Lymphedema may restrict the function of an arm or leg, cause discomfort and affect the appearance of the limbs. For lymphedema in the arms, repeated lifting may be difficult. Lifting items above the head may also pose a challenge. Survivors may also experience reduced range of motion in the affected arm. For lymphedema in the legs, it may be harder to sit or stand for prolonged periods of time.