The phenomenon of bruising on the feet should consider the following aspects: For bruising on the feet for no reason, the first thing to do is to go to the hospital to test the coagulation function. Generally do a full set of coagulation tests to see the coagulation time, prothrombin changes, can identify the cause. If there is no problem with coagulation, we should consider the problem of the blood system, and we usually have to do routine blood tests in the hospital to check the platelet count. If the platelet count is significantly low, this can cause bruising to occur. In addition, the cause of bruising may also be simple purpura. Purpura is an immune disorder that tends to occur anywhere on the body. If it appears to have purpura on the feet, the phenomenon of bruising on the feet for no apparent reason can also occur.