Here's why you sleep so terribly after drinking

You went out with some friends, had a few drinks, came back home and fell asleep immediately.

But now it's super early the morning after and you're wide awake, feeling like you've had the worst night of sleep of your life.

What happened?

We spoke with nutritionist Karen Ansel to figure out how exactly alcohol messes with your sleep.

At first, alcohol relaxes you.

It's not uncommon to fall asleep pretty much the moment your head hits the pillow after drinking. Ansel says this is because alcohol relaxes you. But despite how deep the sleep you fall into feels, you're really just nodding off.

Alcohol disrupts REM sleep.

According to Ansel, REM (rapid eye movement) refers to the "deep, restorative sleep that makes you feel rested in the morning." This is not the sleep you fall into after tossing back a few beers, cocktails, or glasses of wine.

Alcohol actually interferes with your REM sleep, and decreases the amount of REM sleep you get - meaning that you get less of that vital deep sleep. The more drinks you knock back, the more the alcohol in your system will interfere, and the less REM sleep you get. "So while one drink might be a little bit of a problem, if you're going to have three or four you might feel like you didn't sleep at all," Ansel explains.

Alcohol also disrupts your breathing.

Ansel says that alcohol can also suppress your breathing, effectively bringing on a condition known as sleep apnea. More specifically, there might be periods of a few seconds throughout the night where you stop breathing.

Sleep apnea leaves those afflicted feeling exhausted when they wake up in the morning because their brain has been deprived of oxygen. This not only causes them to routinely wake up, but also feel like they didn't get any rest. Alcohol has that same effect.