Alcohol is metabolized by the liver, in the form of acetaldehyde, which can trigger symptoms such as sweating, flushing, nausea, vomiting, and increased pulse rate. Other symptoms that accompany are dehydration, headaches, joint and muscle aches, fatigue and weakness.

Alcohol is irritating to the stomach wall, increases stomach acid production, and slows gastric emptying, so this triggers nausea and vomiting. If the stomach is empty or does not digest food, and in people with gastric disease, the irritation effect will be heavier.