A bruise, also called a contusion or ecchymosis, is a kind of injury to biological tissue in which the capillaries are damaged, allowing blood to seep into the surrounding tissue. It is usually caused by blunt impact. Bruises often induce pain but are not normally dangerous. Sometimes bruises can be serious, leading to other more life threatening forms of hematoma, or can be associated with serious injuries, including fractures and internal bleeding. Minor bruises are easily recognized by their characteristic blue or purple color in the days following the injury.
The extent of bruising depends on many factors. The state of the tissue (tensed muscle versus relaxed muscle, for example) can make a large difference, as can the effect of being crushed against underlying bone. People also vary in the sturdiness of their capillaries — some people bruise more easily than others.
When stricken, the victim normally feels some pain, although it may not be sharp and may even go unnoticed. The flesh quickly becomes red, tender, and swollen (this, like other effects, varies with the intensity of the bruising). Repeated impacts aggravate the bruising. Over the course of a day, blood seeps into the surrounding tissue while the capillaries are being repaired. The bruise gradually darkens. Over the course of a week or two, the bruise darkens to a livid red, then fades to purple, black, or blue, eventually fading to yellow and disappearing as healing progresses. Normal, light bruises heal completely in a week or two; more severe or deeper bruises may take longer. The striking colors of a bruise are due to hemoglobin and its breakdown products, bilirubin and biliverdin.
The treatment for light bruises is minimal. If swelling is severe, it might be reduced by applying ice or by elevating the affected area. Rest and avoiding re-injury is essential to quick recovery; gentle massage of the area may relieve pain and encourage blood flow, though this should not occur if the massage is painful.
Bruising a tendon can feel very painful and make it difficult to use the muscles surrounding the joint.
If bruising is severe, complications may arise. Excess fluid may accumulate, forming a hard lump called a hematoma. Swelling may also be severe, and pain may be a serious problem. If internal bleeding inside the tissue is very severe, compartment syndrome may occur, leading to disrupted blood flow due to swelling; this can require surgery. More seriously, the impacts that cause severe bruising can also cause other damage: impacts to the torso may damage internal organs, and impacts to the head can be very dangerous. Bones may be broken by similar impacts, and joints can be sprained or otherwise damaged as well. The symptoms of these injuries may appear to be those of simple bruising; if there is any possibility of one of these more severe injuries (difficulty moving an injured limb, severe abdominal bruising or a feeling of liquid under the skin) see a doctor immediately.
Treatments for severe bruising can include RICE: Rest, Ice, Compression and Elevation, as well as painkillers (particularly NSAIDs). Massaging severe bruises will worsen the injury. Later in recovery, some light stretching exercises may be appropriate, but it is probably best to consult a doctor or physiotherapist about longer-term recovery. If a severely bruised muscle is used too early in the recovery process, bone tissue may be formed inside the muscle, leading to lasting stiffness and pain. Severe bruises can be expected to take longer to heal.
The main symptoms are pain, swelling, and skin discoloration. The bruise begins as a pinkish red color that can be very tender to touch. It is often difficult to use the muscle that has been bruised. For example, a deep thigh bruise is painful when you walk or run.
Eventually, the bruise changes to a bluish color, then greenish-yellow, and finally returns to the normal skin color as it heals.
The presence of bruises may be seen in patients with platelet or coagulation disorders. Unexplained bruising may be a warning sign of child abuse or serious medical problems, such as leukemia and meningoccocal infection. Unexplained bruising could indicate internal bleeding or certain types of cancer, and should be evaluated by a doctor. A deficiency in Vitamin C can also make a person more susceptible to bruises from impacts.