Bleeding, technically known as hemorrhaging or haemorrhaging (see American and British spelling differences), is blood escaping from the circulatory system. Bleeding can occur internally, where blood leaks from blood vessels inside the body, or externally, either through a natural opening such as the mouth, nose, ear, urethra, vagina or anus, or through a break in the skin.Hypovolemia is a massive decrease in blood volume, and death by excessive loss of blood is referred to as exsanguination.