What causes swollen ankles?

Standing or sitting for long periods can let fluid collect around the ankles. Varicose veins may make this worse because leg veins do not return blood as efficiently. A sprain, insect bite, or other local irritation can produce swelling on one side. Some medicines can also cause ankle oedema; do not stop a prescribed medicine without advice.

Swelling in both ankles may occur with problems that affect fluid balance, including chronic kidney disease or heart failure. Obesity can add pressure to the veins and make leg swelling more likely. A painful, warm, suddenly swollen one-sided leg needs prompt assessment because deep vein thrombosis is a possible cause.

If the swelling is mild and follows prolonged sitting or standing, raise your legs when resting, move your ankles regularly, and avoid tight socks. Note whether it affects one or both ankles, when it began, and whether it changes during the day. A clinician can review your medicines, examine circulation, and decide whether tests are needed.

Seek urgent medical help for sudden one-sided swelling with pain, warmth, or redness, or for swelling with chest pain, breathlessness, faintness, or coughing blood. Arrange a clinical review if swelling persists, keeps returning, is worsening, or comes with reduced urine, marked tiredness, or breathlessness when lying down.

Ask what pattern of swelling you have, whether a medicine could contribute, and whether your heart, kidneys, or leg veins need checking. You can also ask which movements, supports, or treatment changes are suitable for you.