A bruise develops when blood escapes from damaged blood vessels into the surrounding tissues under the skin, usually as the result of a blow directly to the injured area. The exception is a black eye, which may result from a hit at the temple or forehead, as well as on the eye itself. This happens because the blood follows a gravitational path. Bruised tissues under and around the eye are likely to swell, in some cases causing the eye to shut. Although the skin over a bruise remains unbroken, it quickly becomes discolored, turning reddish initially, then “black and blue” or purple, and finally yellow or pale green, as damaged blood cells die and are reabsorbed into the blood stream. The extent of a bruise is self limiting, because nearby undamaged vessels contract and restrict any further blood flow to that area. Meanwhile, blood platelets collect and activate the clotting mechanism that closes off the break. Unless more serious injuries are present, most bruises will heal themselves in a week to 10 days.
Diagnostic Studies And Procedures
Bruises, also called contusions and hematomas, are usually obvious by their appearance, particularly if they develop as a result of a blow, fall, or dislocation. If they form uneven blotches or remain painful over a long period, medical investigation is warranted, which may include blood tests to measure platelets, clotting factors, and clotting time.
There are no medical treatments for bruises as such. Simple bruises are self healing, and even more extensive ones respond well to self-treatment. Some doctors suggest substituting other pain killers for aspirin as a treatment for bruising, because aspirin is known to disrupt the blood’s clotting mechanism. However, there is little evidence that this approach will make any difference. An ophthalmologist should be consulted promptly if an injury to the eye causes blurred vision or severe pain or if there is bleeding in the eye.
Herbalists recommend applications of a poultice made from the leaves of comfrey steeped in boiling water. This mix should be cooled and applied between gauze layers to the bruised areas. Avoid skin irritation by applying lanolin first. The active chemical agent in comfrey is allantoin, which has a healing effect on skin tissue. Tincture of arnica, or an arnica cream derived from the dried flowers of the plant Arnica montana, is also said to be effective in treating bruises, especially if applied soon after being injured.
Although bruises will heal themselves, prompt self-treatment can sometimes reduce their size and tenderness. During the first 24 hours following the injury, frequent application of an ice pack or cold water compress to the bruised area slows down the bleeding and reduces swelling and pain. After ice treatment, healing through the reabsorbtion of blood cells is promoted by the use of warm compresses or the application of a heating pad. If a bruise forms on an arm or a leg, swelling can be reduced by keeping the affected limb elevated. Bruises that develop in conjunction with a pulled muscle or a sprain in the wrist or ankle should be treated with the standard RICE approach: rest, ice, compression, and elevation. The bruise of a black eye calls for somewhat different self-treatment. To reduce swelling, apply an ice pack or cold compress as soon as possible after being injured; follow with warm wet compresses the next day. There is no value to the folk remedy of applying raw steak to the bruise. Any benefit comes from the coolness of the meat and a compress is more convenient.
Other Causes of Bruises
Sometimes spontaneous bruises occur when there is a serious underlying disease, possibly a bleeding disorder such as hemophilia, or a serious blood disease such as leukemia or aplastic anemia. Long term use of corticosteroid medications can also cause easy bruising, as can vitamin C deficiency. A condition called purpura simplex, which usually occurs in women, is characterized by the spontaneous appearance of bruises on the upper arms, thighs, and buttocks. In most cases, there are no other blood abnormalities and clotting mechanisms are normal. The cause of this easy bleeding is unknown; unless symptoms of an underlying disorder become apparent, it is not a cause for concern, and it requires no special attention.