What causes edema?

Edema is swelling caused by excess fluid retention to your body. Normally it occurs in feet, hands, legs, sometimes overall body. It caused by excess intake of salty foods, impaired trade fluid btw chambers that surrounded tissue & organ. Serious condition of kidney disease can one of causes of edema because kidney reduces the function to excrete unwanted products from body (sodium, potassium, etc.,) which makes little more fluid to circulate in your body & trapped.CHF (congestive heart failure) & cirrhosis of the liver causes edema of the lungs & also an accumulation of fluids in the abdominal cavity . Sometimes chronic venous insufficiency causes edema. During pregnancy or menstruation ,which fluid retention & swelling can seen in the feet , hands which is temporary & expected .

Some of the reasons of edema are as follows-
# increased hydrostatic pressure;
# reduced oncotic pressure within blood vessels.
# increased tissue oncotic pressure.
# increased blood vessel wall permeability e.g. inflammation.
# obstruction of fluid clearance via the lymphatic system.
# changes in the water retaining properties of the tissues themselves. Raised hydrostatic pressure often reflects retention of water and sodium by the kidney.