Here's What's Going On in Your Body When You Crash From Too Much Coffee


There's an unfair truth in caffeine: It's a drug so mainstream and basic that your parents drink it after dinner cocktails, yet the minute you try to kick the habit, the withdrawal hits like a sock full of nickels. The symptoms sound a lot like a regular hangover, but without the fun — headache, fatigue, cloudiness, lower energy and crappy concentration.

In fact, I'm having a caffeine hangover right now. Ow. Owowowowow.


In 2009, researchers from the University of Vermont conducted a study using ultrasound and electroencephalography (EEG) to see what's happening in your head when you're in the middle of a caffeine withdrawal. 

The answer: Some weird stuff.


Caffeine constricts your cerebral arteries, which is mostly what your blood uses to travel around your brain. When that happens, your blood is actually moving at a slower pace from one side of your brain to the other.

After you get used to drinking coffee, those cerebral arteries dilate in anticipation of the caffeine-induced constriction. And so a relationship begins: Your arteries dilate, the caffeine constricts them, and you find yourself at neural equilibrium. Just like you adapt to getting a certain amount of caffeine to function in the morning, your brain anticipates the blood-slowing effect of caffeine's constriction.

But when you abstain from caffeine, your brain doesn't get the memo until it's already dilated, so instead of constricting, the arteries are wide open, letting blood flow freely around your head like a bobsledding team of red cells.

And just like if an actual bobsledding team were to clang around in your head, that hurts like hell.


For hardcore caffeine users, withdrawals, and the symptoms that make you a real jerk in the morning, can last up to a week.

"If you want to stop caffeine use, you should taper yourself off instead of going cold turkey,"  Stacey Sigmon, author of the University of Vermont study, told ABC Science, "that will help avoid some of the classic symptoms, including headache."

The absolutely garbage part about caffeine withdrawal: It barely takes any time to gain a tolerance, and thus a dependence, on caffeine.

"Most of us would think we continue to drink caffeine because it makes us more alert, more focused," Sigmon explained. "But really, after a couple of weeks you probably develop enough tolerance to where, as long as you are taking the same dose each day, you're likely not getting much bang for your buck."

Thanks a lot, body.