Bruising after a sprain is due to local damage to small blood vessels, rupture caused by bleeding, blood in the subcutaneous spread, through the skin can be seen bruising. Bruising sign of injury is not very light, in this case, in the acute stage, that is, within 48 hours of the injury can be cold compresses, cold compresses can effectively promote local vasoconstriction, play a role in reducing bleeding, reduce pain, relieve swelling. After 48-72 hours, the local bleeding has completely stopped, and local hematoma and swelling will remain. At this time, hot compresses can be applied according to the situation to promote local blood circulation, which is conducive to the local hematoma’s mechanization, dissipation and absorption, and at the same time, it is also conducive to the reduction of swelling. It is recommended that patients should go to the hospital for a detailed examination and take regular treatment.