
Hello,
Various possibilities for your symptoms are Gout,ankle arthritis,infection(cellulitis),vascular obstruction like in DVT,
varicose veins, eating a poor diet high in salt and carbohydrates , drugs like laxatives,diuretics,birth control or hormone replacement therapy pills,sodium retention, phlebitis, Allergic reactions, neuromuscular disorders and trauma.Liver,kidney and heart disorders are also important causes,some of which have been ruled out in your case.