Sometimes when you bump a part of your body, such as your elbow, the bump pushes a muscle against a bone. Tiny veins and arteries in the muscle break. Some blood leaks out, and soon, you have a bruise.
A bruise is like an inside out cut. A bruise does not bleed on the outside because the skin is not broken. Instead, the blood moves below the top layer of your skin. The blood shows through your skin as dark blue or black.
As the bruise heals, it may change colours. Each colour is lighter than the last. This means that the blood is moving back into your body. The muscle is getting well.
Burns are another way you can hurt yourself. When your skin burns, the burned spot puffs up. A blister forms. A blister is like a puffy little pocket in the layers of your skin. The top layer of skin pulls away from the layers underneath it, and the space fills with liquid. The top layer keeps germs from getting into the blister.
Again, your cells start to heal your burned skin. Slowly the liquid moves back into your body, and your blister heals.
Picture Credit : Google
