Edema, most commonly noticed in the hands, legs, ankles and feet, results when excess fluid becomes trapped in the tissues, causing swelling. Edema occurs when tiny blood vessels known as capillaries leak fluid, which can result from damage to or increased pressure within the capillaries or from lowered protein levels. Kidney damage or disease, cirrhosis, chronic venous insufficiency, congestive heart failure and an inadequate lymphatic system can all cause edema.
Kidney Disease
Any damage to tiny blood vessels located in the kidneys, known as glomeruli, which filter waste and excess water from the blood, leads to nephrotic syndrome. Nephrotic syndrome results in low levels of protein, or albumin, in the blood, which can lead to fluid accumulation and edema.
People with known kidney disease typically are unable to eliminate enough fluid and sodium from their blood. According to the Mayo Clinic, the extra fluid and sodium increases pressure within the blood vessels, causing edema. The edema typically resides in the person's legs and feet.
Cirrhosis
Scarring of the liver, known as cirrhosis, interferes with liver function. Cirrhosis of the liver causes changes in the hormones and chemicals that regulate fluids in the body and increases the pressure within the large blood vessel, known as the portal vein, which carries blood from the intestine, spleen and pancreas into the liver. These problems can result in fluid accumulation in people's legs and feet.
Chronic Venous Insufficiency
A long-term condition known as chronic venous insufficiency, or CVI, ensues when the valves in the veins of the legs become weak or damaged. CVI develops because of a partial vein blockage or blood leakage around the valves of the veins. CVI veins have problems sending blood back to the heart, and therefore the blood remains stagnant within the veins of the legs, increasing pressure and causing swelling, or edema.
Congestive Heart Failure
Congestive heart failure, a chronic condition, results when one or both of the lower heart chambers, known as ventricles, lose their ability to pump blood efficiently to the rest of the body. As the heart's pumping action is lost, blood backs up in other areas of the body, causing congestion and edema in the lungs, legs and feet.
Inadequate Lymphatic System
The lymphatic system helps clear excess fluid from tissues. The lymphatic system becomes damaged from either lymphedema or a disease or medical condition, such as cancer or an infection. Lymphedema, meaning a swelling of lymph passages, causes lymphatic obstruction. Whether the lymphatic system damage is caused from lymphedema or a disease or medical condition, the lymph nodes and lymph vessels do not work properly, and edema of the legs and feet follow.
