suddenly feels like you're falling in your whole body twitches what is that

well that's a jerk, a hypnic jerk to be precise, a hypnic jerk sometimes called a sleep start is

the scientific term for what happens when you jump in your sleep there the

involuntary muscle twitches that happened in your arms legs or even your

entire body as you drift off to dreamland, most people get them roughly

70% of the population jumps in their sleep, but why do they happen

there are two main theories based on neural science and evolution most common

explanation is that as you fall asleep there are two different systems your

brain that are basically battling each other. System number one, a network of

nerve cells called the reticular activating system is just below your

cerebral cortex the big wrinkly part of your brain. when this system is in full

force you feel alert, it essentially helps keep you awake. system number two

call the ventrolateral preoptic nucleus or VLP0 for short is located near the

optic nerve and influences your sleep cycle, the VLP0 sometimes referred

to as the sleeps switch, as you fall asleep each night or during nap time

the VLP0 system begins to take control from the reticular activating

system during this hand off from one system to another the alert part of your

brain can still sometimes stimulate your muscles causing twitches, these hypnic jerks are

last-ditch attempts by the reticular activating system to maintain control of

your body as you more or less choose to sleep, system number one usually

seized control the system number two the VLP0 and the hypnic jerks eventually

stopped, so these jerks are thought to be the result of a sleeping waking war

happening in your body each time you try to get some shut-eye, another less common

theory for what causes hypnic jerks involve our primate ancestors. some scientists think

that the ancient primate brain associated relaxation or the beginning

stages of sleep with falling out of a tree, hypnic jerks were a way of waking the

primate up quickly so they could take action and possibly break their fall.

so these muscular twitches might have stayed with us as we evolved over the years.

whatever causes hypnic jerks they're nothing to worry about according

to most experts but if you don't love getting jolted awake feeling like you're

plummeting near-death there are some steps you can take to limit how many

sleep start to experience things like high caffeine consumption, working out in the evening hours,

high stress levels and lack of sleep can cause more frequent

and more intense hypnic jerks, so cutting back on the coffee, getting your workout

done in the morning and managing your stress levels and sleeping patterns

might result in fewer hypnic jerks, but like I said they're not dangerous

so if they don't bother you, no need to ditch your afternoon latte, there're bigger jerks

out there to battle after all. Thanks to all of our patrons on patreon for not being jerks

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