What causes a person to vomit blood?
Stomach ulcer or severe gastritis. If you vomit blood and also have a burning or gnawing pain in your tummy, the most likely causes are a stomach ulcer or severe inflammation of the stomach lining (gastritis). Bleeding occurs when the ulcer or inflammation damages an underlying artery.
When should you go to the doctor for vomiting?
Schedule a doctor's visit. Make an appointment with your doctor if: Vomiting lasts more than two days for adults, 24 hours for children under age 2 or 12 hours for infants. You've had bouts of nausea and vomiting for longer than one month.