Waking up with a hangover can make you feel a little bit dumb, and not just because you regret ripping shots of whiskey and sending Snapchats of your face in a dog filter to everyone you know. In addition to all the lovely physical side effects you experience the morning after drinking, you might also feel a little mentally foggy or as if you just can't think straight. But that feeling isn't just in your head — a hangover can actually impair your ability to think clearly.
Basically, we know that drinking alcohol really screws with a few important parts of your brain: the cerebellum, which controls motor coordination; the limbic system, which handles emotion and memory; and the cerebral cortex, which is responsible for our ability to think, plan, solve problems, remember, and learn, according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA). But alcohol's effects in these areas don't simply vanish once you stop drinking — or even the morning after.
Plus, being hungover makes it even harder for your brain to do its job. A 2009 study in the International Journal of Neuroscience found that hangovers have a negative effect on cognitive functions — including visual, memory, and intellectual processes. Another 2003 study in the journal Neuropsychopharmacology found that people are less alert when they're hungover. That may be why a hangover makes it feel like you can only handle binge-watching The Great British Bake Off, moseying outside to get a breakfast sandwich, and not much else.
Also, hangovers just make you feel like crap. "Part of feeling dense or dull is because you just feel sick," says Aaron White, PhD, senior scientific advisor to the director of the NIAAA. "And if you don't feel well, it's hard to pay attention and be motivated." But being able to pay attention to the right things is crucial for all sorts of cognitive functions. So if you can't pay attention to anything other than your throbbing headache, you'll probably also have trouble with more complex tasks. Remember: A hangover is literally the end result of exposing your body to toxins, he says. So in a cruel sort of way, you feeling terrible makes sense.
A hangover is also kind of like a mini withdrawal symptom from alcohol, Dr. White says. "If you like drinking because it produces euphoria and reduces anxiety, the next day you get a rebound effect," he explains. You might notice an increase in anxiety and shakiness, or perhaps just generally feel "blah."
However, you might have heard that alcohol can "kill brain cells," but that's not totally true. What drinking really does is cause inflammation in your brain. "In order for your neurons to function, the delicate brain circuits require a pristine balance of fluid and chemicals around neurons," Dr. White says. But the day after you drink, things will be a bit out of whack in your brain, so they might not be able to function properly until you're feeling better.
The bottom line is that there are lots of good scientific reasons why you feel slightly stupid after drinking. Researchers have tried to understand exactly what happens when you have a hangover, but a lot is still unclear because the science of hangovers is kind of confusing. What is clear is that hangovers can truly make you feel terrible — physically, mentally, and emotionally. So if it seems like you just can't think when you're hungover, that's because you kind of can't.
Dr. White says you should just do whatever it is that makes you feel better or more comfortable when you're hungover. In most cases, trying to get hydrated can help you feel better. "Some people feel better after some caffeine, or after their body gets moving — and some just [have to wait it out]," he says.
Beyond that, there's not a whole lot you can do to feel less dumb when you're nursing a hangover at your desk. But understanding that your brain might actually be (temporarily) impaired might help you slog through the rest of the day. In other words, blame it on your brain — and the whiskey shots.