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Edema is swelling that occurs when too much fluid is trapped in the tissues of the body, particularly the skin.

There are different causes and types of edema. For example, pulmonary edema affects the lungs, while pedal edema causes swelling in the feet.

Edema usually starts slowly, but onset can be sudden. It is a common condition, but it can also be a sign of a serious condition.

This article will explain what edema is and how to recognize it, as well as the different types of and treatments for edema. It will also look at possible complications of the condition.

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Edema, or water retention, causes a part of the body to swell.Share on Pinterest
Edema, or water retention, causes swelling in the affected part of the body.

Edema refers to swelling and puffiness in different areas of the body.

It most often occurs in the skin, especially in the hands, arms, ankles, legs, and feet. However, it can also affect the muscles, bowel, lungs, eyes, and brain.

Edema mainly occurs in older adults and pregnant people, but anyone can experience it.

Symptoms depend on the underlying cause, but swelling, tightness, and pain are common.

A person with edema may also notice:

  • swollen, stretched, and shiny skin
  • skin that retains a dimple after a few seconds of pressure
  • puffiness of the ankles, face, or eyes
  • aching body parts and stiff joints
  • weight gain or weight loss
  • decreased urine production
  • fuller hand and neck veins
  • visual anomalies

Symptoms can also depend on the type of edema a person has and which part of the body it affects.

Treatment will also depend on the cause of edema.

Diuretics are a type of medication. They help get rid of excess fluid by increasing the rate of urine production by the kidneys. Different types work in different ways.

A doctor will recommend a specific treatment plan for macular edema, pulmonary edema, and other types of edema.

A person with edema could also try wearing compression garments and doing specific exercises to help.

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Wearing compression stockings can help reduce the swelling and discomfort associated with edema.

Some self-care techniques can help reduce or prevent edema.

These include:

  • reducing salt intake
  • losing weight, if appropriate
  • getting regular exercise
  • raising the legs when possible to improve circulation
  • wearing supporting stockings, which are available to purchase online
  • not sitting or standing still for too long
  • getting up and walking about regularly when traveling
  • avoiding extremes of temperature, such as hot baths, showers, and saunas
  • dressing warmly in cold weather

A masseuse or physical therapist may help remove the fluid by stroking firmly in the direction of the heart.

Oxygen may be useful for treating some types of edema. For example, an individual with cardiogenic pulmonary edema may need additional oxygen if they have difficulty taking in enough.

Oxygen delivered through the nose may improve poor vision associated with diabetic macular edema, according to older research from 2004.

However, some research suggests that hyperbaric oxygen therapy can increase the risk of pulmonary edema.

There are many types of edema. Each one can indicate a range of further health conditions.

Types include:

  • Peripheral edema: This affects the feet, ankles, legs, hands, and arms. Symptoms include swelling, puffiness, and difficulty moving certain parts of the body.
  • Pulmonary edema: This occurs when excess fluid collects in the lungs, making breathing difficult. This can result from congestive heart failure or acute lung injury. It is a serious condition, it can be a medical emergency, and it can lead to respiratory failure and death.
  • Cerebral edema: This occurs in the brain. It can happen for a range of reasons, many of which are potentially life threatening. Symptoms include:
    • headache
    • neck pain or stiffness
    • whole or partial vision loss
    • changes in consciousness or mental state
    • nausea
    • vomiting
    • dizziness
  • Macular edema: This is a serious complication of diabetic retinopathy. Swelling occurs in the macula, which is the part of the eye that enables detailed, central vision. The person may notice changes to their central vision and how they see colors.
  • Pitting edema: With this type, which can occur in peripheral edema, pressure applied to the skin leaves an indent or pit in the skin.
  • Periorbital edema: This refers to inflammation and puffiness around the eye or eyes. The puffiness is due to fluid buildup and is usually temporary.

Edema can occur in other locations as well, but those mentioned above are the most common.

Edema can indicate one of many serious health conditions. It is important for a person to check with a doctor if they are concerned about any kind of swelling.

Edema can result from circulatory problems, infection, tissue death, malnutrition, total body fluid overload, and electrolyte problems.

There are many other possible causes of edema, including the following.

Heart failure

If one or both of the lower chambers of the heart cannot pump blood properly, blood can accumulate in the limbs, causing edema.

Kidney disease or kidney damage

The body of a person with a kidney disorder may not be able to eliminate enough fluid and sodium from the blood. This puts pressure on the blood vessels, which causes some of the liquid to leak out. Swelling can occur around the legs and eyes.

Damage to the glomeruli, which are the capillaries in the kidneys that filter waste and excess fluids from the blood, can result in nephrotic syndrome. One symptom of this is a low level of the protein albumin in the blood. This can lead to edema.

Liver disease

Cirrhosis affects liver function. It can lead to changes in the secretion of hormones and fluid-regulating chemicals and reduced protein production. This causes fluid to leak out of the blood vessels into surrounding tissue.

Cirrhosis also increases pressure within the portal vein, which is the large vein that carries blood from the intestines, spleen, and pancreas to the liver. Edema can occur in the legs and abdominal cavity.

Certain medications

Certain medications can also increase the risk of edema.

These include:

Pregnancy

During pregnancy, the body releases hormones that encourage fluid retention and the body to retain more sodium and water than usual. The face, hands, lower limbs, and feet may swell.

When a person is resting in a reclined position during pregnancy, the enlarged uterus can press on a vein known as the inferior vena cava. This can obstruct the femoral veins, leading to edema.

During pregnancy, the blood clots more easily. This can increase the risk of deep vein thrombosis (DVT), which is another potential cause of edema.

Eclampsia, which results from pregnancy-induced hypertension, or high blood pressure, can also cause edema.

Dietary factors

A number of dietary factors can also affect the risk of edema, such as:

  • consuming too much salt (in people who are susceptible to developing edema)
  • malnutrition, wherein edema can result from low protein levels in the blood
  • a low intake of vitamin B 1, B 6, and B5

Diabetes

Some complications of diabetes include:

  • cardiovascular disease
  • acute renal failure
  • acute liver failure
  • protein-losing enteropathy, which is an intestinal condition that causes protein loss

These complications, and certain medications for diabetes, can result in edema.

Diabetic macular edema is the swelling of the retina in diabetes.

Conditions affecting the brain

Some causes of swelling in the brain include:

  • Head injuries: A blow to the head may result in an accumulation of fluids in the brain.
  • Stroke: A major stroke can result in brain swelling.
  • Brain tumors: A brain tumor will accumulate water around itself, especially as it builds new blood vessels.

Allergies

Some foods and insect bites may cause edema of the face or skin in people who have allergies or sensitivities to them. Severe swelling can be a symptom of anaphylaxis.

Swelling in the throat can close a person’s airway, so they cannot breathe. This is a medical emergency.

Problems with the extremities

Some extremity-related causes of edema include:

  • A blood clot: Any blockage, such as a clot in a vein, can prevent the blood from flowing. As pressure increases in the vein, fluids start to leak into the surrounding tissue, causing edema.
  • Varicose veins: These usually occur because valves become damaged. Pressure increases in the veins, and they start to bulge. The pressure also increases the risk of fluids leaking into the surrounding tissue.
  • A cyst, growth, or tumor: Any lump can cause edema if it presses against a lymph duct or vein. As pressure builds up, fluids can leak into surrounding tissue.
  • Lymphedema: The lymphatic system helps remove excess fluid from tissues. Any damage to this system — from a surgical procedure, an infection, or a tumor, for example — can result in edema.

Miscellaneous conditions

Some other possible causes of edema include:

  • Prolonged immobility: People who are immobile for a long time can develop edema in their skin. This can be due both to fluid pooling in gravity dependent areas and the release of antidiuretic hormone from the pituitary.
  • High altitude: This, combined with physical exertion, can increase the risk of edema. Acute mountain sickness can lead to high-altitude pulmonary edema or high-altitude cerebral edema.
  • Burns and sunburn: The skin reacts to burns by retaining fluid. This causes localized swelling.
  • Infection or inflammation: Any tissue that is infected or inflamed can become swollen. This is usually most noticeable in the skin.
  • Menstruation and premenstruation: Hormone levels fluctuate during the menstrual cycle. During the days before menstruation, levels of progesterone are lower, and this may cause fluid retention.
  • Birth control pills: Any medication that contains estrogen can cause fluid retention. It is not uncommon for people to gain weight when they first start using birth control pills.
  • Menopause: Around menopause, hormone fluctuations can cause fluid retention. Hormone replacement therapy can also trigger edema.
  • Thyroid disease: Hormonal imbalances associated with thyroid problems can lead to edema.

Untreated edema can lead to:

  • painful swelling, with pain that gets worse
  • stiffness and difficulty walking
  • stretched, itchy skin
  • infection in the area of swelling
  • scarring between the layers of tissue
  • poor blood circulation
  • loss of elasticity in the arteries, veins, and joints
  • ulcerations on the skin

Any underlying condition needs medical treatment to prevent it from becoming more serious.

Edema occurs when fluid builds up in the body. This causes swelling, which can sometimes be painful.

There are several potential causes of edema, including pregnancy, heart failure, liver disease, and certain medications. The treatment a person receives will depend on the cause.