Lymphedema is a set of pathologic conditions that are characterized by the regional
accumulation of excessive amounts of interstitial protein-rich fluid. These occur as a result of
an imbalance between the demand for lymphatic flow and the capacity of the lymphatic
circulation. Lymphedema can result from either primary or acquired (secondary) disorders.
In this review, the pathophysiology, classification, natural history, differential diagnosis, and
treatment of lymphedema are discussed.