According to The Mayo Clinic, "A bruise forms when a blow breaks small blood vessels near your skin's surface, allowing a small amount of blood to leak out into the tissues under your skin. The trapped blood appears as a black-and-blue mark". Blood vessels are the arteries, veins, and capillaries that transport blood throughout the body. Medline Plus, a service of the U.S. National Library of Medicine, affirms that there are three different kinds of bruises, subcutaneous, periosteal, and intramuscular. Subcutaneous bruises ensue from damaged blood vessels just under the skin. An intramuscular bruise is caused by trauma inflicted on the blood vessels within a muscle, usually those closest to the skin. Periosteal bruising occurs when injury is done to the outer layer of a bone and the surrounding vessels.
A bruise usually begins as a dark brown, purple, or black color and then fades over time. According to Dr. Edward F.Group III, founder of the Global Healing Center, "Most bruises will disappear after 2 weeks, and some go away even sooner." The formation of a bruise typically requires a significant amount of impact to the area. However, there are several attributing factors that may cause a person to bruise more easily than what is typical.
Advanced age may contribute to excessive bruising in several ways. One is the weakening and thinning of capillary walls, common in the elderly. As the tissue becomes fragile, it tends to break more easily. Skin also thins with age, and the layer of fat underneath diminishes. This process may be accelerated by excessive exposure to direct sunlight during one's lifetime.
Medications that thin the blood can facilitate bruising by inhibiting the clotting factor. Blood vessels are usuaully broken as a result of some non-specific trauma or injury to an area, like bumping your shin or toe against a piece of furniture. Involvement in certain athletic activities may also presuppose an individual to bruising. Bleeding from minor blood vessel breakage normally stops on its own. When left unchecked, enough blood may accumulate beneath the skin to form a bruise. According to literature published in the Merck Medical Library, " When clotting is poor, even a slight injury to a blood vessel may lead to major blood loss." One study conducted by the National Criminal Justice Reference Service, examined the potential of spontaneous bruising in 101 volunteers above the age of 65. Over a two week period, authors Laura Mosqueda M.D., Kerry Burnight Ph.D., and Solomon Liao M.D observed, "Individuals on medications known to have an influence on bruising are more likely to have multiple bruises." Medicines that may increase bruising include aspirin, warfarin (Coumadin), clopidogrel (Plavix) and corticosteroids. Some dietary supplements like ginko and fish oil produce the same effect.
Excessive bruising could also indicate a much more serious condition. Bruises that occur on the back, chest, or stomach area may denote internal bleeding. Those that appear behind the ear could be the result of a skull fracture. Bruises that become numb, are of greater than average size or inordinately painful may indicate that accumulating blood is putting undue pressure on nerve endings. Equally hazardous is bleeding that simultaneously occurs elswhere, such as the nose, mouth, or rectum. Any of these symptoms should be immediately examined by a physician.