Edema is a form of swelling caused by excess fluids trapped in the tissues of your body. It is most commonly found at the ankles, feet, legs, arms and hands. Edema can be a result of a temporary condition such as during pregnancy or after an injury. Edema can also result from heart, kidney or liver disease, or it can be a side effect of a medication. Edema can also be peripheral, which means it is found in the ankles, feet, legs, arms, and hands, or it can be central, which means it is found around internal organs such as the lungs.