Bruise

A discoloured area under the skin caused by leakage of blood from damaged capillaries (tiny blood vessels). At first, the blood appears blue or black; then the breakdown of haemoglobin turns the bruise yellow. If a bruise does not fade after a week, or if bruises appear for no apparent reason or are severe after only minor injury, they may be indications of a bleeding disorder. (See also black eye; purpura.)