A hemorrhage is when blood flows out of the natural circulation. It can be a simple bleeding in a small amount, in the case of a small skin wound, or a large and life-threatening loss of blood. The bleeding can be externalized through the skin, or through a natural orifice, which is the case of epistaxis, a nose bleed; or hemoptysis, bleeding that is respiratory in origin, leaving through the mouth; or hematemesis, coughing up blood from the digestive tract; rectal bleeding, red blood from the anus of gastrointestinal origin; or melena, black, digested blood leaving through the anus. But the hemorrhage can be more difficult to identify for non-externalized bleeding: this is called internal bleeding, which is the case in the brain or meningeal hemorrhage in the brain or other organ bleeding often in the abdomen. Severe bleeding requires emergency treatment .