Alcohol acts as a diuretic. Early in the night (before the seriously regrettable stuff), your body pulls that water from your blood plasma. But as the night wears on, you dehydrate even more. At this point, your body will pull water from the brain to keep your other organs functioning properly. “When the brain doesn’t have enough water it stretches the [cell] membranes, which causes that hangover headache we are all familiar with,” says Damon Raskin, M.D., the chief medical officer for Cliffside Malibu, a drug and alcohol rehab center.

To read the full article, click here.