Drinking too much alcohol is the root cause of a hangover. People have different tolerances to alcohol, so it can be difficult to predict how many drinks will cause a hangover. Anytime you drink to intoxication, you run the risk of having a hangover the next day. Specifically, here’s what happens to your body when you have a hangover.
You become dehydrated. Alcohol increases urination, so your body loses fluids. That dehydration contributes to hangover symptoms like thirst, headache, and fatigue.
Your sleep gets interrupted. You may fall asleep faster after a few drinks, but drinking alcohol interferes with brain activity, which leads to fragmented sleep. You then wake up feeling groggy and tired.
Your stomach feels upset. Alcohol irritates the stomach lining and increases the release of stomach acids. That can lead to nausea and stomach pain.
Inflammation increases. Alcohol ramps up inflammation throughout the body, which can leave you with an overall sense of malaise.