Throwing up blood, also known as hematemesis, can be a serious medical emergency that requires immediate attention. If an alcoholic starts throwing up blood, it may be a sign of a bleeding ulcer or esophageal varices, which are swollen veins in the esophagus.

If you or someone you know is an alcoholic and is experiencing vomiting blood, seek medical attention right away. This could involve calling 911 or going to the emergency room. Prompt medical attention is important to diagnose and treat the underlying cause of the bleeding.