Edema

Swelling caused by excess fluid trapped within body tissues usually in the hands, arms, feet, ankles, and/or legs. It can be a sign of other medical problems.

Under normal circumstances the vascular system delivers nutrients to the cells through the capillary beds. Fluid diffuses out of the vessels and into the space between cells following the hydrostatic pressure gradient that exists at the beginning of the capillary beds. Exchange of nutrients and waste occurs