Lymphedema is a chronic disease marked by the increased collection of lymphatic fluid in the body, causing swelling, which can lead to skin and tissue changes. The chronic, progressive accumulation of protein-rich fluid within the interstitium and the fibro-adipose tissue exceeds the capacity of the lymphatic system to transport the fluid. Swelling associated with lymphedema can occur anywhere in the body, including the arms, legs, genitals, face, neck, chest wall, and oral cavity. There are many psychological, physical, and social sequelae related to a diagnosis of lymphedema. Lymphedema is classified as either (genetic) primary lymphedema or (acquired) secondary lymphedema.
The lymphatic vessels transport lymph. Lymph is composed of white blood cells, triglycerides, bacteria, cell debris, water, and protein. It has a composition comparable to blood plasma. The lymph drainage system is complex and comprises initial lymphatics (lymph capillaries), pre-collectors, collectors, lymphatic trunks, and lymph nodes. Topographically, the lymph system is distinguished as superficial (subcutaneous) and deep (subfascial). The superficial system drains the skin and subcutis areas. The deep system drains muscles, joints, tendon sheaths, and nerves. Both systems are connected via the perforating vessels, which conduct lymph fluid from the subfascial areas to the surface.
Signs and symptoms of lymphedema include distal swelling in the extremities, including the arms, hands, legs, feet; swelling proximally in the breast, chest, shoulder, pelvis, groin, genitals, face/intraoral tissues; restricted range of motion in the joints because of swelling and tissue changes; skin discoloration; pain and altered sensation; limb heaviness; and difficulty fitting into clothing.