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You're drifting off to sleep, when suddenly you feel like you're plunging off a cliff -- and you jerk awake. The jolt is disorienting, and you must try again to fall asleep.
As many as 70 percent of people experience sleep starts or hypnic jerks while falling asleep, says Dr. William Kohler, medical director of the Florida Sleep Institute and director of the pediatric sleep services at Florida Hospital, Tampa.
“A hypnic jerk or sleep starts are a perfectly normal occurrence that is almost universal,” explains James K. Walsh, executive director and senior scientist at St. Luke’s Sleep Medicine and Research Center in St. Louis.
“It involves a total body experience where your muscle contracts therefore your limbs jerk or your body twitches. They generally occur during the transition between wakefulness and sleep. All of these things are very, very brief, lasting a half second or less.”
Hypnic jerks are myoclonus twitches, or involuntary muscle spasms, but sleep starts occur during hypnagogia, the stage when the body is falling asleep.
While most people have felt hypnic jerks, a small number of people experience the frightfully-named exploding head syndrome, the sensation that there is an explosion, crashing cymbals, or thunder near (or in) one’s head. Exploding head syndrome is so rare that it is mostly reported by individual case studies. While exploding head syndrome distresses people with it, both Walsh and Kohler stress that this, too, is normal and not a sign of any problem, physical or mental.
“They’re healthy people with a very unpleasant experience,” explains Walsh.
Movement plays a role in sleep — involuntary twitches commonly take place during rapid eye movement (REM) sleep, but these jolts occur with dreams whereas hypnic jerks occur before the body can dream.
“Some people think [hypnic jerks] might be associated with anxiety and stress or with unusual or irregular sleep schedules. The exact nature of why it occurs is not really clear,” says Kohler.
While the cause remains unknown and little research is done on hypnic jerks (they are considered harmless and normal and are often too fleeting for observation), sleep doctors and researchers theorize about why they occur.
Walsh says that he, like others in the field, speculate that as the body falls asleep it goes through mini-REM-type periods where the muscles slacken and dreamlike feelings might start.
Brainwaves occurring during hypnagogia resemble brainwaves during REM sleep, which could explain the physiological changes that occur when falling asleep. During REM our heart rate, breathing, and nervous system act erratically and if the body experiences flashes of REM while entering sleep, these irregularities could contribute to twitches. Most assume the hypnic jerks occur because the body begins relaxing.
While the visceral sensation of tumbling out of bed or plummeting off a cliff feels scary as it occurs, most people do not experience sleep starts frequently enough to seek medical treatment. Kohler says if hypnic jerks inhibit sleep, a person should consult a sleep medicine doctor. He adds that a better sleep routine -- such as having a resting period prior to bed; avoiding food, smoking, and caffeine; and going to bed and waking at the same time -- improves overall sleep.
Related:
- Loud crash at 3 a.m.? It may be your exploding head
- Waking a sleepwalker is totally safe -- for them
- Study: Sleepwalking more rampant than thought
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I have had this happen but usually only when I am under stress and extremely tired. I have also noticed that right before falling asleep in one of these periods, even the slightest normal noises sound like a rifle shot right next to my ear....it is as if all my senses are super charged for just a few moments and highly sensitive to any sort of sound, light, or even touch. I always thought it was that you were physically and mentally tired but the brain just couldn't shut down and stop worrying about whatever was stressing you out.
Did this article just go to some length only to point out we don't know what causes body jerks as we fall asleep?
Why? No one knows. Thanks for wasting our time, msnbc. Did someone actually get paid to write this? Ridiculous.
Happens to me once in a while. Usually just laugh it off. Makes my wife jump too. I can usually tell her "Yep, I was falling again."
Happens to me all the time. Multiple times a night. I've had the loud crashes too that husband swears are in my head. and to the commenter above..yes they appear to give an in depth explanation that they have no explanation for what causes it. Oh the irony.
I've experienced exploding head syndrome twice. It's creepy. There was no pain but I reached up to check the top of my head expecting to find blood or something. I wish someone could explain this one.
I hate when this happens. As a general rule, I have difficulty falling asleep, but then when I'm falling asleep, all of a sudden it's like I'm falling through air only to jolt and realize I haven't actually moved. I do have to say, it hasn't happened since I've started listening to an app on my phone to talk me into sleep. The relaxation app talks you into letting everything relax and slowly sinking deeper, so I don't have the jolt of feeling like I'm falling.
They have no idea what causes it yet they site lack of sleep, stress, alcohol, as possibilities.
That **IS** what causes it!! duh!!
I get hypnic jerks on occasion, a couple times/year. And WAY less than I did years ago. I used to get them before my son was born and I was working two jobs, and only got 5-6 hrs sleep/night, had poor diet, etc. Well guess what? My son was born in 2002, I only work PT now and they've almost stopped. I only get them after a stressful day or lack of sleep for a while. I don't drink/smoke/do drugs/take medication so I have no way to know if that's a cause. Sorry, I do take Imitrex on occasion for migraines. When I take 100mg it knocks me out and I will experience hypnic jerks, sleep paralysis, and dreaming while dreaming (I think that's worse than hypnic jerks), which is sort of like lucid dreaming.
Because I hate Dr's and no dr knows my body like I do when something like this happens I do everything in my power to find the cause so I can fix it MYSELF. My opinion? It happens when falling from one stage of sleep to a deeper one very quickly. (which can also considered a "wake-initiated lucid dream"). Your muscles are relaxing, letting out tension, sometimes faster than they can handle and thus the muscle spasm. Lack of sleep, stress, alcohol, drugs, medications, poor diet, poor hydration ALL contribute to hypnic jerks/exploding head syndrome.
Falling from one stage of sleep to a deeper one quickly (or skipping a stage of sleep, ie going from state 1 to stage 3 or 4) can also cause Sleep paralysis. THIS is scary and happened often to me as well-- YEARS ago, mostly before my son was born. Again, stress, lack of sleep, poor diet/hydration, drugs, alcohol, medications can cause this.
I believe hypnic jerks/sleep paralysis and lucid dreaming are very closely connected. When I am having an episode of sleep paralysis I've taught myself what exactly is happening so I can wake myself up. I'm asleep, and dreaming (REM Sleep), yet i know I'm dreaming and wake myself up. Sleep paralysis is scary, and not because I'm paralyzed. Subciounsly I know I'm not. It's because there's a fear of some unknown, darkness, falling, not knowing what's around me. It's hard to explain. But I rock myself back and forth and wake myself up. Sometimes I can "catch" myself before it happens because I can tell if I'm falling asleep to deep too fast. At that point I sit up or get up and walk around for 5 minutes to wake myself up so I will subsequently fall asleep more smoothly.
Congrats if u read all this, lol
Yes, the article is complete speculation or lack of. My son has been doing the "jerk", as I call it, from the moment he was born, so I can't imagine, unless the stress is attributed to transition from womb to breathing air, that these movements are stress related. Like I said, he is 2 now, been doing this his entire life and I use this as a cue to know when he is asleep.
I use to have these all the time but it would definitely happen a lot more when I was sleep deprived, stressed, or just in random occasions when I would be falling asleep when I was supposed to be awake (school, church, etc). But I'd have to say I don't think I've had them within the past 2 years even once.. Kind of strange.
When we finally release the tension of the day and allow our body to relax it feels as if we are falling....DUH...thats why they have always called it falling asleep...
Wow, an article that tells nothing about something. Science is amazing. Journalism is profound.