Death occurs after vomiting black blood, commonly due to the following reasons: 1. Gastrointestinal bleeding. Bleeding inside the stomach or intestines, the bleeding volume is relatively large, thus leading to hemorrhagic shock, if not treated in time, there is a risk of death. 2, respiratory tract obstruction. If the person is unconscious after vomiting blood or blood is accidentally sucked into the airway, thus blocking the airway and leading to breathing difficulties, asphyxiation and death. 3, cranial head injury. After the head injury, resulting in skull base fracture will also vomit blood, but this situation leads to death, there may be cranial injury, skull base fracture combined with intracranial injury, such as brain contusion, brain hemorrhage, or even brain stem injury, resulting in severe brain edema, brain compression, resulting in brain hernia formation and death.