Edema is swelling caused by excess fluid trapped in your body’s tissues. Although edema can affect any part of your body, it’s most commonly noticed in the hands, arms, feet, ankles and legs.
Edema can be the result of medication, pregnancy or an underlying disease — often heart failure, kidney disease or cirrhosis of the liver.
Taking medication to remove excess fluid and reducing the amount of salt in your food often relieves edema. When edema is a sign of an underlying disease, the disease itself requires separate treatment.
Edema occurs when tiny blood vessels in your body (capillaries) leak fluid. The fluid builds up in surrounding tissues, leading to swelling.
Mild cases of edema may result from:
- Sitting or staying in one position for too long
- Eating too much salty food
- Premenstrual signs and symptoms
Edema can be a side effect of some medications, including:
- High blood pressure medications
- Nonsteroidal anti-inflammatory drugs
- Steroid drugs
- Certain diabetes medications called thiazolidinediones
In some cases, however, edema may be a sign of a more serious underlying medical condition. Diseases and conditions that may cause edema include:
- Congestive heart failure. When one or both of your heart’s lower chambers lose their ability to pump blood effectively — as happens in congestive heart failure — the blood can back up in your legs, ankles and feet, causing edema. Heart failure can also cause swelling in your abdomen. Sometimes it can cause fluid to accumulate in your lungs (pulmonary edema), which can lead to shortness of breath.
- Cirrhosis. Fluid may accumulate in your abdominal cavity (ascites) and in your legs as a result of liver damage (cirrhosis).
- Kidney disease. When you have kidney disease, extra fluid and sodium in your circulation may cause edema. The edema associated with kidney disease usually occurs in your legs and around your eyes.
- Kidney damage. Damage to the tiny, filtering blood vessels in your kidneys can result in nephrotic syndrome. In nephrotic syndrome, declining levels of protein (albumin) in your blood can lead to fluid accumulation and edema.
- Weakness or damage to veins in your legs. Chronic venous insufficiency, in which the one-way valves in your leg veins are weakened or damaged, allows blood to pool in the leg veins and cause swelling. Abrupt onset of swelling in one leg accompanied by pain in your calf can be due to a clot in one of your leg veins. Seek medical help promptly.
- Inadequate lymphatic system. Your body’s lymphatic system helps clear excess fluid from tissues. If this system is damaged — for example, by cancer surgery — the lymph nodes and lymph vessels draining an area may not work correctly and edema results.
Signs and symptoms of edema include:
- Swelling or puffiness of the tissue directly under your skin
- Stretched or shiny skin
- Skin that retains a dimple after being pressed for several seconds
- Increased abdominal size
When to see a doctor
Make an appointment to see your doctor if you have swelling, stretched or shiny skin, or skin that retains a dimple after being pressed. Seek immediate medical attention if you experience:
- Shortness of breath
- Difficulty breathing
- Chest pain
These symptoms can be a sign of pulmonary edema, which requires prompt treatment.
If you’ve been sitting for a prolonged period, such as on a long flight, and you develop swelling and pain in a leg that won’t go away, call your doctor. Persistent leg pain and swelling can be a sign of a blood clot deep in your veins (deep vein thrombosis, or DVT).