Edema

Definition

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 your hands, arms, feet, ankles and legs.

Edema can be the result of underlying medical conditions, certain medications or pregnancy.

Identifying and treating the underlying cause of edema is key to effectively controlling it. Self-care measures coupled with medication that removes excess fluid usually can effectively treat edema.

Symptoms

Signs and symptoms of edema include:

• Swelling or puffiness of the tissue under your skin (subcutaneous tissue)
• Stretched or shiny skin
• Skin that retains a dimple after being pressed for several seconds
• Increased abdominal size

Causes

Edema occurs when tiny blood vessels in your body (capillaries) leak fluid. This leakage can result from damage to or increased pressure in the capillaries. When your body senses the capillaries are leaking, your kidneys begin to retain more sodium and water than normal to compensate for the lost fluid from your blood vessels. This increases the amount of fluid circulating through your body, which causes the capillaries to leak more. The fluid from the capillaries leaks into the surrounding tissue, causing the tissue to swell.

The cause of some mild cases of edema can be simply sitting for too long or eating too much salty food. Edema also is a common premenstrual sign. Women who are pregnant often retain excess fluid, which can cause swelling of their hands, feet and face.

Edema can be a side effect of some medications, including:

• Drugs that open blood vessels (vasodilators)
• Calcium channel blockers (calcium antagonists)
• Nonsteroidal anti-inflammatory drugs (NSAIDs)
• Estrogens
• 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 loses its ability to pump blood effectively — as happens in congestive heart failure — the blood can back up in your legs, ankles and feet, causing edema.
• Cirrhosis. This disease causes scarring of your liver, which interferes with liver function, causing changes in the hormones and chemicals that regulate fluids in your body, as well as increasing pressure within the large blood vessel (portal vein) that carries blood from your intestine, spleen and pancreas into your liver. These problems can result in fluid accumulating in your legs and your abdominal cavity (ascites).
• Kidney disease. When you have kidney disease, your kidneys may not be able to eliminate enough fluid and sodium from your blood. The extra fluid and sodium increases pressure in your blood vessels, causing edema. Edema associated with kidney disease usually occurs in your legs and around your eyes.
• Kidney damage. Damage to the tiny blood vessels in your kidneys (glomeruli) that filter waste and excess water from your blood can result in nephrotic syndrome. One result of nephrotic syndrome is low levels of protein (albumin) in your blood, which can lead to fluid accumulation and edema.
• Weakness or damage to veins in your legs. Chronic venous insufficiency (CVI) is a condition in which the veins in your legs are weakened or damaged and can’t pump enough blood back to your heart. The remaining blood increases pressure in the veins, causing swelling.
• Inadequate lymphatic system. Your body’s lymphatic system helps clear excess fluid from tissues. If this system is damaged — either due to lymphedema that occurs on its own (primary lymphedema) or because of a disease or medical condition, such as cancer or an infection (secondary lymphedema) — the lymph nodes and lymph vessels draining an area may not work correctly and edema results.

Risk factors

The following diseases and conditions can increase the risk of developing edema:

• Congestive heart failure
• Cirrhosis
• Kidney disease
• Nephrotic syndrome
• Chronic venous insufficiency (CVI)
• Deep vein thrombosis
• Lymphedema

Due to the fluid needed by the fetus and placenta, a pregnant woman’s body retains more sodium and water than usual, increasing the risk of edema.

Taking some medications — such as drugs that open blood vessels (vasodilators), calcium channel blockers (calcium antagonists), nonsteroidal anti-inflammatory drugs (NSAIDs), estrogens and certain diabetes medications called thiazolidinediones — can increase your risk of edema.

When to seek medical advice

Make an appointment to see your doctor if you have any of the following signs or symptoms:

• Swelling or puffiness of the tissue under your skin (subcutaneous tissue)
• Stretched or shiny skin
• Skin that retains a dimple after being pressed for several seconds
• Increased abdominal size

Shortness of breath, difficulty breathing and chest pain may be signs and symptoms of edema in your lungs (pulmonary edema). Pulmonary edema is a potentially life-threatening condition. Diagnosis and treatment of pulmonary edema differ from other forms of edema. If you have signs or symptoms of pulmonary edema, seek immediate medication attention.

Tests and diagnosis

To determine the underlying cause of edema, your doctor will ask questions about your health history and your condition, including how long you’ve had signs and symptoms of edema, if the signs and symptoms come and go (intermittent) or if you have them all the time (persistent), and if you’ve had edema before.

Your doctor will also perform a physical exam. If your doctor suspects an underlying medical condition as the cause of edema, he or she may recommend tests, such as a chest X-ray, blood tests or urine tests, to diagnose the condition.

Complications

If left untreated, edema can cause:

• Increasingly painful swelling 
• Difficulty walking
• Stiffness
• Stretched skin, which can become itchy and uncomfortable
• Increased risk of infection in the swollen area
• Scarring between layers of tissue
• Fibrous deposits in tissues
• Decreased blood circulation
• Decreased elasticity of arteries, veins, joints and muscles
• Increased risk of skin breakdown (ulceration)

Treatments and drugs

Treating edema usually involves:

• Treating the underlying cause of edema
• Taking medication to increase your kidneys’ output of water and sodium (diuretics). Diuretics often used to treat edema include thiazide diuretics, furosemide (Lasix) and spironolactone.
• Limiting salt in your diet to decrease fluid retention, as recommended by your doctor

In some cases, diuretics may not be appropriate to treat edema, such as in people who have chronic venous insufficiency or in pregnant women.

Lifestyle and home remedies

The following may help decrease edema and keep it from coming back. Before trying these self-care techniques, talk to your doctor about which ones are right for you.

• Movement. Moving and using the muscles in the part of your body that’s affected by edema may help pump the excess fluid back to your heart. Ask your doctor about exercises you can do that may reduce swelling.
• Elevation. Hold the swollen part of your body above the level of your heart for at least 30 minutes, three or four times a day. In some cases, elevating the affected body part while you sleep may be helpful.
• Massage. Stroking the affected area toward your heart using firm, but not painful, pressure may help move the excess fluid out of that area.
• Compression. If one of your limbs is affected by edema, your doctor may recommend you wear compression stockings, sleeves or gloves. These garments keep pressure on your limbs to prevent fluid from collecting in the tissue.
• Reduce salt. Follow your doctor’s suggestions about limiting how much salt you consume.
• Avoid temperature extremes. Sudden temperature changes, very hot and very cold temperatures can make edema worse. Avoid hot baths, showers, hot tubs and saunas. Protect yourself from sunburn. Dress warmly when going out in cold temperatures and take precautions to protect yourself from frostbite.