Swollen ankles are usually caused by an accumulation of excess fluid in the tissues, a condition called edema. This fluid buildup can be due to many factors, including standing or sitting for long periods, eating too much salty food, being overweight, pregnancy, or side effects of certain medications. Other causes include injuries like sprains, infections, chronic venous insufficiency (problems with blood flow in the leg veins), blood clots, or underlying health problems such as heart, liver, or kidney disease. Inflammation and immune responses can also cause swelling. Sometimes swollen ankles appear with skin changes, pain, or redness, which may require medical attention. Elevating the legs, gentle exercise, and wearing comfortable shoes can help reduce swelling. If the swelling is sudden, severe, associated with pain, redness, or other symptoms like shortness of breath, it is important to see a doctor promptly as it could signal more serious conditions like blood clots or heart failure.