What Causes Black and Blue Marks?
If you fall or receive a sharp blow, you may get a painful bump that soon turns black and blue. When you bruise yourself, tiny blood vessels inside your skin break. And blood from the injured blood vessels oozes into the hurt spot.
The blood that gets trapped in the bruise becomes dark and discolored and makes the bruise black and blue.
Later, the black-and-blue mark turns green and yellow and finally disappears as the trapped blood is gradually absorbed by the body. Sometimes an ice pack will help to lessen the swelling and the discoloration of a bruise.
A bruise, also called a contusion, forms because the soft tissues of your body have been bumped. Some people bruise easily, whereas others may have tougher skin tissue.
When these soft tissues are injured, small veins and capillaries under the skin sometimes break. Red blood cells leak out of these blood vessels. These red blood cells that collect under your skin cause that bluish, purplish, reddish, or blackish mark. That’s where black-and-blue marks get their name — from their color under the skin.
Bruises go through colorful changes as the body begins to heal itself. The color changes mean that your body is metabolizing, or breaking down, the blood cells in the skin. This is the process that your body goes through to repair itself.