Bruise is an injury to the skin and underlying tissues that produces bleeding under the skin. A bruise is also called a contusion. Most bruises are caused by a sudden blow that compresses or crushes the soft tissues, such as the skin and muscles. A severe blow can penetrate to the bone and cause a bone bruise.
Bruises are often painful and are accompanied by swelling and tissue discoloration. Tissue discoloration occurs as a result of blood seeping from injured blood vessels to the surface layers of the skin. As the bruise heals, the blood breaks down to pigments that are gradually absorbed into the bloodstream, changing the colors of the bruise. Ice packs applied to the skin immediately after the injury occurs can help relieve pain and inflammation and can help control bleeding. Bruises that restrict movement should be seen by a physician.