In lymphedema, fluid accumulates in the lymphatic vessels, resulting in the painless swelling of a limb. There are various possible causes, including obstruction of the lymphatic vessels by cancer cells or parasitic worms.
Surgical removal of lymph nodes or radiation therapy to an area containing lymph nodes may also result in lymphedema.
Rarely, it may be due to an inherited condition in which the lymphatic vessels fail to develop properly.
In some cases, it occurs for no known reason.
Lymphedema is usually a lifelong condition, and treatment is aimed at relieving symptoms.