Ever been falling asleep, your eyes drifting shut, peace washing over you like waves on the shore and then bam, God says no and you jolt awake because you felt like your bed just disappeared out from under you? Because it’s great, now you’re just stuck in bed staring at the ceiling, wide awake. Fun. Anyway, why have we been cursed to this cruel fate? Why do you feel like falling in your sleep just as you’re about to drift off?
It’s Called a Hypnic Jerk
You’re probably not surprised to learn that there’s an actual name for this phenomenon, because you’re definitely not alone in experiencing it. There are a couple alternate names like hypnagogic or myoclonic jerk and sleep starts/twitches.
Sometimes hypnic jerks come with hallucinations. Which is absolutely horrifying if you’ve ever experienced one. Hallucinations with hypnic jerks are different from night hags, though both occur in the transitory between sleeping and waking. If you have hallucinations as you are waking up, those are the night hags.
Further Reading: What Are Night Hags?
Most of the literature around the actual cause of hypnic jerks just floats around theories. Some hold that it’s a way to last-minute abort sleep in case there’s some kind of threat around you as to drift off (a hallucination, perhaps). Prime issue, of course, is that nowadays most of the people who are looking up hypnic jerks aren’t going to bed with the need for constant vigilance. So when your brain decides that you’ve fallen off a cliff in bed for no reason, there was probably some weird misfire. But the sensation of falling may be some part of your brain that’s still operating in a bygone era when people slept in trees, or some other way for your brain to double check if it did everything it needed to get ready for bed. Did you eat or drink enough, stuff like that. It’s like asking if you left the stove on, but for your body. There’s not a lot of evidence for these theories, though (particularly the branch one).
Others suggest that it’s some misfire as your body prepares for REM sleep. While you’re in REM, you’re most likely to dream–so your body paralyzes itself to keep you from walking or flailing around. In theory. We all have a sleepwalking friend (or maybe we are the sleepwalking friend). But this is why sleep paralysis occurs out of REM, it’s the body still being paralyzed but also kinda still dreaming. It’s important to note that hypnic jerks do not occur during REM sleep, and they occur during the non-rapid eye movement sleep cycle. That’s why it happens normally when you’re about to fall asleep.
Hypnic jerks are more likely to occur if you have stimulants in your system. Particularly nicotine or an excessive amount of caffeine. Generalized stress and anxiety can also contribute to hypnic jerks, not having enough magnesium or iron in your diet, and even strenuous exercise before bed. Having a bad sleep schedule is also a good way to mess with yourself, but if your sleep schedule is absolute garbage you’re probably a teenager or student in college/postsecondary education–hypnic jerks are not going to be the worst thing you’re getting from terrible sleep habits. Generally speaking, if you’re annoyed with the sensation, most will probably suggest having healthier sleep habits.
There’s also a case where a woman had hypnic jerks possibly induced by escitalopram. In the same study we just linked, though, they couldn’t find any other significant cases or even case studies on the relationship between selective serotonin uptake inhibitors (SSRIs) like escitalopram and jolting awake in your sleep. Their conclusion was “hey sometimes prescription drugs have unique side effects and we should think about that sometimes”.
If you’re worried about hypnic jerks, you can rest assured that at the very least, they’re not related to epileptic seizures, and are generally pretty normal. They’re the most frequent in children and early adolescence.
Sleepy animals are cute so look at some here.