What Really Happens to Your Brain When You’re Hungover

By Jenn Rose Smith

The Sunday Scaries. Hangxiety. No matter what you call it, we’ve all been there. Your head is throbbing, you can’t even figure out how to navigate your Favor app (which is further complicated by the fact your eyes are welling up with tears from that stupid Hallmark movie on tv.) All this begs the question: what’s really happening in our brains after a night of one-too-many drinks?

I did some investigating on the topic and found out that the answer is a complex one. Depending on your genetics, gender, weight, and how much alcohol you consumed, our hangover symptoms (and their severity) can vary widely. That said, there are certain universal truths that reflect the way alcohol affects our brains the morning after.

The cool part is that hangovers really do serve a biological purpose — they’re our bodies way of telling us to chill the F out on drinking. So the next time you’re struggling through an intense, soul-destroying day on the bathroom floor, take comfort in the scientific facts listed below, and remember:

This too shall pass.

image by because i’m addicted

1. The membrane that encases your brain shrinks, which makes for a solid headache.

Alcohol shrinks and disrupts brain tissue in general. “It’s a diuretic and causes our system to shed water,” say the experts at Stanford University. “The more water we lose the more dehydrated we get and the more likely we are to experience a hangover. The headache of a hangover is actually caused by the shrinkage of our brain dura (the membrane that encases our brain) due to dehydration.”

image via rover

2. Serotonin and dopamine levels drop hard, making you feel hyper sensitive and super sad.

“Alcohol causes an increase of the ‘happy hormones’ – dopamine, serotonin and endorphins,” say the medical experts at Health Orange. “This is why alcohol induces feelings of euphoria, but by the next morning, there is a deficit of these hormones, which is why depression and unhappiness are among the most common signs of a hangover.”

image by emerson fry

3. Your brain circuits become inflamed, so you actually become (temporarily) slow and dumb.

Everyone knows that drunk driving is dangerous, but recent studies have proven that hungover driving is majorly scary, too. That’s because your ability to focus, retain information, and make decisions drops during a bad hangover. “In order for your neurons to function, the delicate brain circuits require a pristine balance of fluid and chemicals around neurons,” explains Dr. White at Refinery29. “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.”

image via modern hepburn

4. Cortisol levels flare, causing big time anxiety.

We’ve all experienced “hangxiety,” which is a direct result of increased cortisol levels in the brain. “Although we need cortisol to respond to stress, excess levels of the hormone can lead to improper stress responses, altering our mental status, metabolism, and more,” says science and health writer Kevin Loria. “Those high irregular cortisol levels can make us less able to deal with the regular stresses of life.”

image by the coveteur

5. Your lateral habenula goes to work, creating massive feelings of guilt.

Neuroscientists at the University of Utah have actually identified the part of the brain that creates hangover guilt. It’s called the lateral habenula (the “LHb”) and it’s activated by negative experiences. So when your body’s sick from a hangover, the LHb kicks in by creating feelings of guilt. It’s the human body’s fascinating way of trying to teach itself a lesson: don’t do this again. Ever.