This is Why Your Body Suddenly Jolts When You’re Falling Asleep

Drifting off to dreamland isn’t always smooth sailing. Sometimes you experience some unexpected sensations on the path to sleep. Maybe you’ve had this experience: Just as you’re drifting off to sleep, you suddenly feel like you’re falling off a cliff. Your muscles clench, jerking you back awake.

It’s far from a relaxing feeling, but it’s nothing to be worried about — or lose sleep over. Those muscle spasms are called hypnic jerks, and they’re a natural phenomenon.


“They occur when your muscles contract involuntarily on the cusp between wakefulness and falling asleep,” says Dr. Ingemaud Gerber, medical director for Evolve Retreats. “They are caused by sudden muscle contractions or muscle relaxation.”

Here are a few answers to frequent questions about this strange feeling some of us experience as we’re falling asleep.


Are Hypnic Jerks Normal?

Hypnic jerks are common. Most people — as many as 70 percent — have felt them at some point.

“It involves a total body experience where your muscle contracts therefore your limbs jerk or your body twitches,” James K. Walsh, executive director and senior scientist at St. Luke’s Sleep Medicine and Research Center in St. Louis, told NBC.


What Causes Hypnic Jerks?

Scientists still don’t quite know what causes them, psychologist Tom Stafford reported for the BBC.

And though we’re usually paralyzed while we sleep, “Hypnic jerks seem to be a sign that the motor system can still exert some control over the body as sleep paralysis begins to take over,” he wrote.

Pixabay | Wokandapix

Can You Prevent Hypnic Jerks?

Sleep deprivation, as well as poor sleep habits, will make you more susceptible to hypnic jerks.

“While the physiology of these involuntary movements remains unknown, we do know that you’re more likely to experience hypnic jerks if you have poor sleeping patterns or have been sleep deprived,” Dr. Andrew Weil shared on his website.


Meditation or other relaxation techniques and avoiding caffeine before bedtime can help you avoid experiencing hypnic jerks.

“Anxious thoughts or stress may keep your brain active even as your muscles try to relax as you drift off to sleep,” Gerber said.

Looking for some other tips to help you fall asleep easier? Here are some for you to try:

Lower The Temperature In The Room

Even if you don’t wake up drenched in sweat, it might be time to lower the thermostat. According to WebMD, the ideal temperature for sleep is between 65 and 72 degrees Fahrenheit. A mild drop in temperature can actually help induce sleep.

Keep The Lights Off

It might be tempting to flick on the light switch once you’ve woken up, but try to keep the room dark. Turning on the light can mess up your body’s natural circadian rhythms, as your body interprets light as a signal to become alert. This can suppress the hormone melatonin, which is necessary to help make you feel sleepy.

Jot Down Your Thoughts

If you’re laying in bed with your mind racing, going over everything you have to do tomorrow, it’s time to let some of those thoughts out. Spend a little time journaling or quickly jotting down a to-do list to get these looming feelings off your chest. Research shows that journaling before bed results in reduced worry and stress, increased sleep time, and improved sleep quality.


As long as you follow better sleep hygiene and relaxing techniques, you’ll be able to calmly drift into dreamland.

Additional reporting by Carina Wolf.