Lymphedema is a collection of fluid that causes swelling (edema) in the arms or legs. This type of edema occurs when the amount of lymph fluid in a person's arm or leg exceeds the body's ability to remove it, and the fluid then collects in the tissues of the limb.

One of the causes of lymphedema is surgery to remove lymph nodes, usually during cancer treatment. Lymphedema causes the blood vessels and lymph channels in the limb to increase in size and number. It also reduces oxygen delivery to the tissues, interferes with wound healing, and can lead to infection. Lymphedema is often a permanent condition and may not completely go away, even with treatment. The amount of swelling may fluctuate at different times.

Lymphedema is often managed with physiotherapy and compression sleeves or stockings.