Edema is swelling that is caused by fluid trapped in your body’s tissues. Edema happens most often in the feet, ankles, and legs. Other parts of the body, such as the face and hands, can also be affected. Edema can happen to anyone.
What causes edema?
Edema has many possible causes.
Edema can occur as a result of gravity, especially from sitting or standing in one place for too long. Water naturally gets pulled down into your legs and feet.
It can happen from a weakening in the valves of the veins in the legs (a condition called venous insufficiency). This problem makes it hard for the veins to push blood back up to the heart, and leads to varicose veins and a build up of fluid in the legs.
Certain diseases — such as congestive heart failure and lung, liver, kidney, and thyroid diseases — can cause edema or make it worse.
Being pregnant can cause edema in the legs as the uterus puts pressure on the blood vessels in the lower trunk of the body.
In addition, too much salt from your diet can make edema worse.