Bruising on the legs is a condition that can be caused by trauma. Trauma can cause capillaries to rupture, resulting in a small amount of subcutaneous bleeding and subcutaneous bruising. Frequent subcutaneous bruising may also be caused by other diseases, such as thrombocytopenic purpura, allergic purpura, aplastic anemia, due to a decrease in platelets and abnormal blood clotting, thus prone to subcutaneous bruising. Long-term oral administration of anti-platelet drugs, such as aspirin and Bolivar, can cause subcutaneous bruising. Patients who apply drugs such as low molecular heparin or warfarin for anticoagulation are also prone to bruising. If the bruising on the legs is caused by trauma, you can apply heat to the local area to promote blood circulation and eliminate the bruising, or you can use Chinese medicine to activate blood circulation and remove blood stasis for treatment. If subcutaneous bruising occurs frequently, you need to go to the hospital for further examination to see if there are other diseases, such as subcutaneous bruising from the application of antiplatelet drugs or anticoagulant drugs, you also need to go to the hospital for examination and adjust the dosage of the drugs according to the examination results.