Bleeding is any loss of blood from the body. Bleeding can occur either internally or externally. It can occur through a natural opening such as the vagina. Most bleeding occurs through a break in the skin.
Bleeding is caused by injury to blood vessels, the structures that hold the blood. The injury can be minimal or life threatening. The most common causes of injuries to blood vessels are cuts and puncture wounds. Automobile accidents, gunshot wounds, household tools, machinery, and construction equipment often cause injuries. There are a significant number of visits to emergency rooms for bleeding injuries.