Sometimes, ‘falling asleep’ is a distressingly literal term.
That nighttime jolt your body subjects you to is a surprisingly common experience ― up to 70% of us experience hypnic jerks, and no, the term doesn’t refer to that ‘close-up-magician-slash-mentalist’ you dated in your teens (OK, maybe that’s just me).
“Hypnic jerks, also known as hypnagogic jerks or ‘sleep starts,’ are involuntary muscle contractions that some people experience as they fall asleep. They may feel like muscle twitches,” said Medical News Today. And Dr. Karan Raj, who’s known for sharing his medical knowledge and debunking health myths on TikTok, recently shared a post on the topic.
“This is the human version of auto-save,” the doctor begins. Here’s what he has to say on the phenomenon: It could be a millennia-old safety mechanism.
When we were (basically) apes, most of us slept in trees ― at least, that’s what experts reckon. And while the sleeping sitch was a good way to protect us from predators, it wasn’t exactly conducive to a great night’s kip.
Dr. Raj says in his video that the nighttime habits of our ancestors could well have had longer-term effects on our current dozing habits. He told viewers that jolts are likely to happen in the hypnogagic state, right when you’re transitioning from being awake to being asleep. “We don’t really know why it occurs, but there are a few interesting theories,” he says, adding that “some believe it’s a byproduct of evolution, where our bodies experience muscle relaxation as the potential to fall out of a tree ― and it jerks them to ensure we’re still safe.”
He adds that “there’s evidence stress, anxiety, caffeine, and exercise can cause or exacerbate these jerks.” They could also be a form of A/B testing your sleeping status Dr. Raj says that “perhaps the most interesting theory is that hypnic jerks are our bodies’ way of testing to see if sleep paralysis has truly taken hold.”
Though sleep paralysis can refer to the terrifying visions some people see at night, it’s also a vital part of sleep, locking in our muscles during the REM stage “to ensure you don’t act out your dreams.” “Some believe hypnic jerks occur when the brain sends electrical signals to the muscles to test this paralysis,” the doctor said, “And a jerk means it’s not set in ― test failed.” Pretty smart, right? Again, we don’t know for sure what causes the twitches ― but the theories are far from snore-worthy.
