Risk factors

If you are pregnant, your body retains more sodium and water than usual due to the fluid needed by the fetus and placenta. This can increase your risk of developing edema.

Your risk of edema may be increased if you take certain medications, including:

• High blood pressure medications
• Nonsteroidal anti-inflammatory drugs
• Steroid drugs
• Estrogens
• Certain diabetes medications called thiazolidinediones

A chronic illness — such as congestive heart failure or liver or kidney disease — can increase your risk of edema. Also, surgery can sometimes obstruct a lymph node, leading to swelling in an arm or leg, usually on just one side.