A bruise on the leg does not necessarily affect the D2 polymers results, depending on the bruise on the leg. D2 polymer is a specific degradation product formed by activation and hydrolysis of fibrin monomers, mainly from cross-linked fibrin plaques dissolved by fibrinolytic enzymes, and the elevated level suggests that there is a tendency for thrombosis or hypercoagulability in the body. Bruising on the legs may be caused by trauma or coagulation system lesions. Trauma-induced subcutaneous bleeding and bruising generally does not affect the D2 polymerase results, but if the leg bruising is caused by abnormal coagulation function, then the D2 polymerase level will be abnormal. Bruised legs have different effects on D2 polymers depending on the specific cause of the disease. If there is coagulation dysfunction that needs to be treated in a timely manner in order to avoid persistent bleeding or deep vein thrombosis, a systematic examination should be done in a timely manner, and any abnormality should be treated in a timely manner.