We throw up when drunk because vomiting is the body's natural protective reflex to get rid of harmful toxins, specifically acetaldehyde, a toxic substance produced when the liver breaks down alcohol. When a person drinks too much alcohol too quickly, the liver cannot process all the acetaldehyde, triggering the body to vomit to expel the excess toxin. Alcohol also irritates the stomach lining, causing acid buildup and nausea that can lead to vomiting. Additionally, chronic or excessive drinking can cause gastritis, an inflammation of the stomach lining, which further contributes to nausea and vomiting. Vomiting after drinking helps remove alcohol from the body before it is fully absorbed, although it can cause dehydration and other risks if excessive.
