Why Do We Twitch When We're Falling Asleep?

A majority of people feel like they're falling when first going to sleep, resulting in twitches. What is this jerking night spasm?

This video was a collaboration with our friends at AllTime Numbers. Check out their video for 'Sleep in Numbers' here:

LINKS:

"Extreme hypnagogic jerk"

Good evening BrainStuff. I'm Cristen Conger and we need to have a talk about your little sleep problem.

You know what I'm talking about... the one where you're just about to fall blissfully asleep, when you suddenly feel you’re falling, as if someone threw you out of a tree.

What's important is that you're not alone. According to the American Academy of Sleep Medicine, up to 70 percent of us experience this falling sensation and then twitch or jerk in our sleep.

Science and medicine refer to any involuntary jerking of our muscles like this as "myoclonus." I know it sounds like a cross between those weird bat things in The Empire Strikes Back and that movie about the haunted mirror, but there are all kinds of twitches classified as myoclonus.

Both contractions and relaxations of muscles fall under this category and the simplest example is when we hiccup. Most forms of myoclonus are fairly normal and are caused by a disturbance in your central nervous system.

The specific type of myoclonus that causes you to twitch in your sleep is called a "sleep start" or a "hypnagogic jerk." These are not hypnotists you've had a bad breakup with. No, hypnagogic jerks -- or "hypnic jerks" as the cool kids are saying -- happen just as you're transitioning between wakefulness and sleep. They're quite common, perfectly normal and some people sleep right through the twitching without even knowing it.

The brief jerking around of your limbs lasts only half a second or less. And one thing we know for sure is that they are not the same as the involuntary twitches you sometimes have during REM sleep while dreaming, or other movements caused by snoring or grinding teeth.

There are two theories as to what’s going on with hypnagogic jerks, but fair warning, neither have evidence to really back them up. And unsurprisingly, both involve our brains inferring that we’re falling… when we’re not.

The first is that hypnagogic jerks are part of our natural transition into sleep. It’s possible that our nerves misfire when our muscles calm down, because our brain assumes that their relaxation means we’re falling.

The second idea is that these spasms are reflexes we still retain as evolved primates. You know, if you believe in that sort of thing. This could be designed to keep you from falling out of a tree you’re sleeping in, causing you to quickly react. But as the old Japanese proverb goes “Saru mo ki kara ochiru.” Even monkeys fall from trees.

So myoclonus isn’t 100% understood. And we don’t know why hypnagogic jerks happen. But… there are a few things we believe can make them worse. Stress, too much caffeine, intense exercise, and smoking are all on the list. Y’know, the usual. But if you’re experiencing them constantly and they keep you from sleeping, you should go talk to your doctor.

SOURCES:

while you were sleeping. Good Health (Australia Edition), Dec2009

A Case of the Jerks by Kaitlyn Syring, University Daily Kansan, February 28, 2008

ASK TIP SHEET. By: Romano, Andrew, Newsweek, 00289604, 3/27/2006, Vol. 147, Issue 13

[evalouise]

I hate the twitches but i fall asleep straight after

[xHaniffax]

I've heard about this before but one of the theories I read about for why it may occur could possibly be because as we're falling asleep and relaxing, our brain thinks our body's functioning is declining and that we're dying (not necessary falling to death) and the violent jerk ensures we're still alive. But who knows.

[maddieandlilylovesyou]

true when i sleep i relax but then i feel like someone pushed me so then i wake scared then i calm down LOL

[brokenhatemachine]

I mentioned this to my doctor years ago. He said it’s from anxiety. It’s very annoying. I am just about to fall asleep and my whole body twitches. Then I have to start the whole process over again. Then I begin to anticipate it happening again. The anticipation worsens the anxiety and causes me to twitch more. It’s a vicious cycle.

[nsowers]

We should all go have words with this Larry guy.

[Leggo-Of-My-Draco]

Does anyone else start falling asleep and literally DREAM of falling in some way (slipping down stairs, falling from bed, etc?)
I dream EVERY TIME when I have hyping jerks, it’s extra terrifying.
And it happens almost every night! Is this normal?!

[jimmynuarin]

I almost experience this everyday. I'm glad that I'm not alone. ㅋㅋㅋㅋ

[annaf]

I only get that twitching when I'm really exhausted and just about to drift into sleep (and it stops me from it which is annoying). But I have no sensation of falling. I used to think it's an overexcited and worn out brain trying to remember how to shut itself down...

[puntabachata]

They happen because you are switching between outer physical senses and inner dream senses. If you reflexively react to hypnagogia, your body jerks because you are not fully paralyzed for dreaming, a protective mechanism called REM atonia, which keeps you from acting out your dreams physically.

[aprilbrowning]

I never feel like I am FALLING but when I close my eyes getting ready to fall ASLEEP one of my legs TWITCH HARD at times I hurt myself after that I fall to sleep

[zerogenic]

Someone punches me in my sleep.
Does that mean he's a hypnagogic jerk?

[spderweb]

I get that Twitch right before falling asleep because I start going into a dream state and it's always me tripping, getting hit my something, falling in general, etc.

[settingfiretogiants]

My wife knows I'm falling asleep when we're watching a movie whenever this happens haha

[Burrbrryy]

I keep jumping up before I sleep or when I'm half asleep

[Jackkenway]

Wow I have that for sure, God it feels like I'm falling for real, I mean even in my body I feel like I'm literally falling from a building!

[BrainStuffShow]

What is that twitch/spasm when we go to sleep? We collaborated with Alltime Numbers to get your answer!

[gregorybrian]

When one meditates, it is quite common to twitch and jerk, sometimes a little bit, sometimes a lot, when approaching a very relaxed state. This is because, all day long, we unconsciously suppress those bodily impulses so folks don’t look at us funny. Often, those impulses are caused by stress. I have a theory that this is the same thing that happens when one has entered that relaxed state upon falling asleep.

[gorcha]

bruh i didn’t feel like i was falling i was just about to fall asleep then all of a sudden my upper body twitched so hard it fully woke me up and couldn’t go back to sleep

[Josmersuero]

I always say that the brain send an electric pulse to our entire body because he think we are dead. The brain does that even if we are awake in a coach.

[F.E.L.I.X.]

I always think of falling down like heaven stairs or something like that then I will literally fall off the bed from how scared I get