Edema causes swelling, most often in the hands, arms, ankles, legs and feet, as a result of fluid retention. Also known as dropsy or hydropsy, edema can sometimes appear suddenly, but most often develops slowly and subtly. The most common type of edema is eripheral edema, and is characterized by swelling of the feet, ankles, legs hands and arms. There are also several types of eye edema, including macular edema (often associated with diabetes), corneal edema and periorbital edema. Swelling of the brain due to fluid retention is known as cerebral edema.

Possible causes for edema include burns, heat, high altitudes, various diseases, surgical procedures, genetics, physical inactivity, pre-menstruation and menstruation, menopause, taking certain medications, taking contraceptive pills, sitting or standing for extended periods and pregnancy.

While pregnant, the female body produces hormones that facilitate fluid retention. Pregnant women tend to retain considerably more water and sodium than women who are not pregnant. Lying down while pregnant for extended periods causes the femoral veins to become obstructed and compressed by the uterus and can often leads to edema. Blood that circulates throughout a pregnant woman’s body clots more easily, which can also be a major contributing factor to pregnancy-related edma. Finally, pregnancy-induced hypertension (also known as high blood pressure) can cause edema as well.