Hangovers seem to be the body’s way of reminding us about the hazards of overindulgence. Physiologically, it’s a group effort: Diarrhea, fatigue, headache, nausea, and shaking are the classic symptoms. Sometimes, systolic (the upper number) blood pressure goes up, the heart beats faster than normal, and sweat glands overproduce — evidence that the “fight or flight” response is revved up. Some people become sensitive to light or sound. Others suffer a spinning sensation (vertigo).
Drinking interferes with brain activity during sleep, so a hangover may be a form of sleep deprivation. Alcohol scrambles the hormones that regulate our biological clocks, which may be why a hangover can feel like jet lag, and vice versa. Alcohol can also trigger migraines, so some people may think they’re hung over when it’s really an alcohol-induced migraine they’re suffering.
Hangovers begin after blood alcohol levels start to fall. In fact, according to some experts, the worst symptoms occur when levels reach zero.
Drink fluids. Alcohol promotes urination because it inhibits the release of vasopressin, a hormone that decreases the volume of urine made by the kidneys. If your hangover includes diarrhea, sweating, or vomiting, you may be even more dehydrated. Although nausea can make it difficult to get anything down, even just a few sips of water might help your hangover.
Get some carbohydrates into your system. Drinking may lower blood sugar levels, so theoretically some of the fatigue and headaches of a hangover may be from a brain working without enough of its main fuel. Moreover, many people forget to eat when they drink, further lowering their blood sugar. Toast and juice are a way to gently nudge levels back to normal.
Avoid darker-colored alcoholic beverages. Experiments have shown that clear liquors, such as vodka and gin, tend to cause hangovers less frequently than dark ones, such as whiskey, red wine, and tequila. The main form of alcohol in alcoholic beverages is ethanol, but the darker liquors contain chemically related compounds (congeners), including methanol. According to Dr. Swift’s review paper, the same enzymes process ethanol and methanol, but methanol metabolites are especially toxic, so they may cause a worse hangover.
Take a pain reliever, but not acetaminophen (Tylenol). Aspirin, ibuprofen (Motrin, other brands), and other nonsteroidal anti-inflammatory drugs (NSAIDs) may help with the headache and the overall achy feelings. NSAIDs, though, may irritate a stomach already irritated by alcohol.
Drink coffee or tea. Caffeine may not have any special anti-hangover powers, but as a stimulant, it could help with the grogginess. Caffeine is a diuretic, though, so it may exacerbate dehydration.
How Much to Drink?
Caffeinated Alcoholic Beverages