No matter your age — unless you're under 21 — you are probably familiar with the throbbing headache, the nausea, and exhaustion following a night of drinking. Back in college, you could simply get up and shake your hangover with a quick workout, but now that you’re getting older, you realize you just can’t drink like you used to.

Why do hangovers get worse as we get older? “All of the effects of alcohol are sort of amplified with age,” David W. Oslin, a professor of psychiatry at the Perelman School of Medicine at the University of Pennsylvania, told the Wall Street Journal. “Withdrawal is a little bit more complicated. Hangovers are a little bit more complicated.”

The main issue stemming from heavy drinking is dehydration, which can account for the headaches and overall feeling of malaise the next morning. As people get older, the amount of body water they hold decreases. “A lot of older people are borderline dehydrated,” Dr. Reid Blackwelder, president of the American Academy of Family Physicians, told the Journal. “They have less body water just from the natural effects of aging.”

Along with less water, there are fewer enzymes — such as alcohol dehydrogenase, which is able to break down alcohol — in older people's systems. As enzyme levels decrease, “you have a prolonged exposure to alcohol and possibly a little bit bigger buzz,” Dr. Gary Murray, acting director of the Division of Metabolism and Health Effects at National Institutes of Health, told the Journal. And though our livers get larger as we age, their function and ability to process alcohol becomes more hindered.

Another possible reason for more severe hangovers is that overall, a person’s tolerance for alcohol may decrease as they get older. People in their 40s and 50s are less likely to have beers with friends after work than people in their 20s and 30s. Less body water, fewer enzymes, and a weaker metabolism paired with a low tolerance, can often be the perfect combination for a day long, or even several day long, hangover. Alcohol impacts how well we sleep — this is true for all ages, not only older adults. “Alcohol in all ages wrecks our REM sleep,” Dr. Alison A Moore, professor of medicine and psychiatry at the David Geffen School of Medicine at UCLA, told the Journal. “Older adults are more likely to have poor sleep. [Alcohol] can make sleep even more fragmented.” Plenty of older adults are also on medications, which are usually considered a dangerous mix with booze.

However, some scientists disagree with the general perception that older people are hit harder with hangovers. A study published in the journal Alcoholism: Clinical & Experimental Research found the opposite: older people were able to handle hangovers better after binge-drinking than young people were. The authors perhaps came to this conclusion because the people they measured overall were more seasoned drinkers than the average person. "We found that the tendency to have hangovers decreased by increasing age," Janne S. Tolstrup, author of the study, said in a press release. "The first explanation that pops up is that this finding would be due to differences in drinking pattern in different age groups. However, trying to account for such differences as much as we could, did not even out the differences in hangover tendency."

Regardless of whether you're 22 or 52, the most useful tip post-drinking in preventing hangovers is water. Drink plenty of water before going to sleep, and you might be able to mitigate the next day's hangover.