Hi and welcome. Swollen ankles and swollen feet are common and usually not cause for concern, particularly if you have been standing or walking a lot. But feet andankles that stay swollen or are accompanied by other symptoms could signal a serious health problem. if you dont recall injury then swelling of the ankles and feet is often an early symptom of venous insufficiency, a condition in which blood inadequately moves up the veins from the legs and feet up to the heart. Normally, the veins keep blood flowing upward with one-way valves. When these valves become damaged or weakened, the blood leaks back down the vessels and fluid is retained in the soft tissue of the lower legs, especially the ankles and feet. Chronic venous insufficiency can lead to skin changes, skin ulcers, and infection. You should treat this with elastic stockings, keeping leg elevated and in severe caes you should see vascular surgeon for further treatment.