Vomiting blood after drinking is likely to be gastric bleeding, which is caused by acute gastric mucosal damage. If the bleeding is small and the patient’s condition is mild, it usually does not require treatment and can heal itself with reasonable dietary regimen. Alcohol has a strong stimulating effect on the gastric mucosa, which can lead to congestion, edema, and even acute erosion and ulceration of the gastric mucosa, resulting in bleeding. Depending on the degree of damage to the gastric mucosa, patients may vomit coffee-like gastric contents or even dark red blood. If the bleeding is small, it can usually heal on its own with dietary modification. However, if the damage to the submucosa causes a lot of bleeding, medication and, if necessary, endoscopy is required to stop the bleeding. If the patient bleeds more than 500 ml or more, then the situation is more serious and shock may occur, requiring a visit to the emergency department. Patients should keep their airways open when they vomit blood after drinking to avoid choking from the blood by mistake. At the same time, it is important to abstain from alcohol, eat more food that nourishes the stomach and pay attention to rest.