dear friend vericose vein is the condition in which veins that have become enlarged and twisted.veins have valves to prevent blood from flowing backwards. leg muscles pump the veins to return blood to the heart against the effects of gravity. when the valves do not work (valvular incompetence), it causes blood to flow backwards and likewise enlarging and twisting the veins even more.this is the vericose vein. the related factors in the cause of vericose vein are prolonged standing, leg injury, abdominal straining etc. the blue/purple staining/spots you noticed on your mother s ankle is due to vericose vein. treatment of vericose vein are surgical, and non-surgical treatment includes elastic stockings, elevating the legs, and exercise and sclerotherapy. so you should counsel your mother not to work on her feet as much as possible. whenever possible elevate both legs,this will pumps blood towards heart. hope this answer will be helpful to you. for more queries plz don t hassitate to ask. get well soon dear friend dr.manu khimani