What is edema?

Edema is swelling that is caused by fluid trapped in your body’s tissues. Edema happens most often in the feet, ankles, and legs, but can affect other parts of the body, such as the face, hands, and abdomen. It can also involve the entire body.

What causes edema?

Edema has many possible causes:

  • Edema can occur as a result of gravity, especially from sitting or standing in one place for too long. Water naturally gets pulled down into your legs and feet.
  • It can happen from a weakening in the valves of the veins in the legs (a condition called venous insufficiency). This problem makes it hard for the veins to push blood back up to the heart, and leads to varicose veins and a buildup of fluid in the legs.
  • Certain diseases — such as congestive heart failure and lung, liver, kidney, and thyroid diseases — can cause edema or make it worse.
  • Some drugs, such as medications that you are taking for your blood pressure or to control pain, may cause or worsen edema.
  • An allergic reaction, severe inflammation, burns, trauma, clot(s), or poor nutrition can also cause edema.
  • Too much salt from your diet can make edema worse.
  • Being pregnant can cause edema in the legs as the uterus puts pressure on the blood vessels in the lower trunk of the body.

What are the symptoms of edema?

Signs that you might have edema include:

  • The affected area is swollen.
  • The skin over the swollen area might look stretched and shiny.
  • Pushing in gently on the swollen area with your finger for at least 5 seconds and then removing your finger will leave a dimple in the skin.
  • You may have trouble walking if your legs are swollen.
  • You may be coughing or have trouble breathing if you have edema in the lungs.

Your doctor will ask you questions, conduct a full exam, and might order tests to determine why you have edema.