What causes a bruise to be black and blue? It seems like they should be red?
A bruise is also called a contusion (say: kun-too-zhun), and it 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 (the tiniest blood vessels) 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 (say: muh-tab-o-lyze-ing), or breaking down, the blood cells in the skin. This is the process that your body goes through to repair itself. Imagine a baseball hits you in the leg. Ouch! Your body will go through the following phases: First, you’ll probably have a bump that will look red or purplish and tender.