When there is bleeding or oozing blood under the skin of the body, the blood is absorbed within the tissues and it will show up as bruises under the skin. In the early stage by cold compress can reduce the bleeding and reduce the expansion of the lump, after the second day, on the surface with hot compress, can accelerate the blood circulation, will bruises dissipate faster. If a small bruise can be eliminated in about 20 days, and if the bruise is more extensive, it can be eliminated in about a month. If the bruise can not be eliminated for a long time, there are two possible situations: one, the bruise is very large, that is, there was a lot of bleeding, through its own absorption needs a period of time, you can continue to use a hot towel external compress, or soak in a hot bath method, to eliminate. Second, the bruise may be in the place where the subcutaneous fat is thin, such as in front of the shin bone, because the blood circulation is very poor, through its own absorption will be very slow, the blood clot in the subcutaneous may form a hematoma, secondary to inflammation and infection and other situations. If necessary, the local skin will be cut open, the internal blood clot will be removed, and the wound will be changed.