[header] How to treat a hangover [title] Drink water. [step] While something so simple might seem ridiculous while you're hugging your toilet, re-hydrating yourself is key to overcoming any hangover. Drink 8 to 10 glasses of water slowly over the course of the morning after you have been drinking. 
Alcohol causes your body to lose water by stimulating your kidneys to excrete more water than you drink, resulting in dehydration. The more alcohol you drink, the more water passes out of your body.