heart and blood vessel disorders
Lymphedema
Primary lymphedema
Primary lymphedema results from having so few lymphatic vessels that they cannot handle all the lymph. The problem almost always affects the legs. Rarely, it affects the arms. Several inherited disorders may cause primary lymphedema. These disorders differ according to the age at which swelling becomes obvious. Rarely, the swelling is obvious at birth, but usually, the lymphatic vessels can handle the small amount of lymph produced in an infant. More often, the swelling appears later in life, as the volume of lymph increases and overwhelms the small number of lymph vessels. The swelling starts gradually in one or both legs. The first sign of lymphedema may be puffiness of the foot, making the shoe feel tight at the end of the day. The shoe may leave indentations in the skin of the foot. (Many people who do not have lymphedema experience swelling after they stand for prolonged periods. They may have indentations around their ankles after they wear ankle socks, but the indentations are much less deep than those of lymphedema, and the surrounding area is not puffy.) In the early stages of primary lymphedema, the swelling goes away when the leg is elevated. This disorder worsens with time. The swelling becomes more obvious and does not disappear completely, even after a night’s rest. 