"Our bodies have lots of filters, which try to keep harmful materials out of dangerous places,” Prescott said. "Before it can be flushed from the system, alcohol has to be metabolized. So the liver turns parts of alcohol into toxic chemicals, which tend to hurt us on the way out.”
Two of the biggest offenders are acetaldehyde and formaldehyde. Yes, says Prescott, your body turns alcohol into embalming fluid.
But once the damage is done, don’t try to ward away the pain with a little "hair of the dog that bit you,” Prescott said. More alcohol will just stretch out the misery.
Instead, try to give your body what it’s missing.
If you’re tired, get some rest. If you’re dehydrated, drink water or fruit juice. But stay away from Tylenol because that will further stress your liver.
Of course the best cure is prevention, Prescott said. "Don’t drink to excess, and you won’t have a hangover to worry about.”