Exsanguination
Alcoholism.  Drinking too much alcohol can damage the liver.  If the liver is damaged, it cannot make blood-clotting proteins (like fibrinogen) as well as a healthy liver does.  This makes alcoholics more likely to bleed dangerously if they get hurt.  Liver damage can also lead to a problem called esophageal varices, which can cause a person to exsanguinate by throwing up blood.