Any type of traumatic injury, such as a fall, can cause capillaries (small blood vessels) near your skin’s surface to break and leak red blood cells. This causes the reddish-purple or “black and blue” appearance of bruises on your skin.
Technically known as contusions, bruises may result from virtually any injury to blood vessels in your skin. As your body begins to heal, and metabolizes the blood cells, the bruise will typically fade to a green, yellow, or brown color before disappearing entirely.
