The common clinical reasons for the appearance of bruises on the ankles include normal physiological changes and obstruction of venous return. 1. Normal physiological changes: If the body is in a standing position for a long time or the legs are compressed, the venous return will be impeded and the blood will fill up in the veins. The veins in the ankle, dorsum of the foot and plantar tissues are relatively shallow, and the veins will become more obvious when they are full. This situation can be normalized after proper rest or decompression, which is a normal physiological change. 2. Venous return obstacle: If there is congenital weakness of vein wall and poor function of vein valves, it may cause poor venous return and make the blood stagnate in the veins, and the clinical manifestation of the diseased people is that obvious veins appear on the back of the feet, ankles and other parts of the foot, and accompanied by symptoms such as weakness and numbness of feet, etc. This situation needs to be treated in regular hospitals. In this case, you need to go to the regular hospital for treatment and wear compression stockings or elevate the affected limbs under the guidance of the doctor in order to alleviate the discomfort.