One of the most common types of injury is a bruise, or contusion. This injury is typically caused by blunt force trauma that breaks blood vessels, allowing the blood to escape. The pooled blood is visible through the skin as a bruise. There are three main types of contusion: subcutaneous, muscular and periosteal.
A subcutaneous bruise forms just below the surface of the skin. This type of injury may be caused by a fall, being hit with an object or running into something. Subcutaneous bruises are typically among the quickest to disappear, but may remain visible for up to two weeks.
Bruises may go deeper into the body and affect the muscles. A muscular contusion may be classified as intramuscular or intermuscular. Intramuscular bruises are less likely to cause visible bruising, as they only involve tearing of the muscle. In an intermuscular bruise, both the muscle and its surrounding sheath are torn. Recovery from an intermuscular bruise is generally quicker, as the blood is able to escape through the tear in the muscle sheath rather than building up inside the muscle itself.
The deepest type of bruise is a periosteal contusion, or bone bruise. This injury penetrates all the way to the bone, causing swelling and pain. Swelling between the bone and its covering, the periosteum, can linger for an extended period of time due to lack of circulation. A periosteal contusion is generally the most painful and long-lasting type of bruise.
In most cases, the injury may be treated by following the acronym RICE, which stands for rest, ice, compression and elevation. Patients should not overuse the bruised body part to promote healing. Ice can be helpful to limit swelling but should never be applied directly to the skin—ice packs or cubes wrapped in towels are best. Compression, or wrapping the bruised area with a bandage, should be performed with care so as not to wrap so tightly that blood circulation is cut off. Elevating the injury above the heart may reduce the amount of blood that pools in the area and therefore minimize swelling and the size of the bruise.
People with certain bleeding disorders, such as hemophilia, and those who take blood-thinning medication are more likely to develop contusions. These patients should monitor all bruises closely, as a large amount of swelling may indicate excessive blood loss. Anyone who notices an increase in unexplained bruising should notify his doctor, who may order testing to rule out bleeding disorders. Bruises that do not heal within two weeks, grow larger or become more painful should also be reported to the patient's doctor for possible examination to rule out more serious injury.