A hypnagogic jerk (aka hypnic jerk or sleep starts) is a sudden, brief, and strong contraction of the body — or a segment of your body — that happens as you’re falling asleep.

Sleep starts usually involve one strong jerk that moves most of your body, with the arms and legs more likely to be affected. This can jolt you awake before you have the chance to fall asleep. In most cases, the movement won’t prevent you from falling asleep (…but your partner might not be so lucky).

So should you be concerned about this unwanted nighttime activity?

What causes hypnagogic jerks?

We don’t really know exactly what causes hypnagogic jerks, but experts have some ideas.

These involuntary movements that happen as you’re falling asleep may be linked to:

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Hypnagogic jerks likely happen at random, usually occurring in that sweet transition spot between being awake and initiating asleep. They may move your whole body or just a specific area. And particularly strong hypnic jerk can make you feel like you’re falling and prevent you from dozing off.

The main symptoms usually include:

  • jerking, jolting, or twitching sensation
  • dreaming or hallucinating
  • feeling startled
  • “falling” sensation
  • tingling feeling
  • sensory flash
  • rapid breathing
  • increased heart rate
  • sweating

While they might seem alarming, hypnic jerks are overall quite harmless.

Some experts classify hypnic jerks as a parasomnia — sleep disorders that involve unusual and undesirable physical events that disrupt your sleep (think sleepwalking and talking). The International Classification of Sleep Disorders (ICSD-3) also classifies hypnic jerks as a sleep-related movement disorder under isolated symptoms and normal variants — which in nonscience speak just means hypnic jerks are a natural phenomenon.

It’s estimated that nearly 70 percent of the population experiences these sleepy-time contractions. And anyone can experience this random phenomenon, regardless of age or gender.

But while the exact cause of hypnic jerks is unknown, experts do have some ideas on why these involuntary jolts happen.

Stress or anxiety

Chronic stress and anxiety can make sleep a real challenge. Feelings of intense fear and worry can mess with your ability to fall asleep and stay asleep, which is why hypnogogic jerks are often associated with stress and anxiety.

Intense or frequent hypnic jerks can also make you afraid to fall asleep, leading to stress and anxiety.


Exercise can have a lasting effect on how well you sleep. But *when* you work out and how intense you work out can determine whether you get a good night’s sleep or a bad night’s sleep.

Intense exercise increases your energy levels, and performing them right before bed can make it more difficult for your body to slow down, relax, and transition smoothly into sleep.

If nighttime workouts are your jam, consider adding more low impact or relaxation-inducing exercises to your routine, like yoga, Pilates, or even a simple stretch sesh.

Sleep deprivation

Not getting enough sleep can have a serious effect on your health. From skin probs and forgetfulness to respiratory issues and poor immune health, there are all sorts of ways that sleep deprivation can spell T-R-O-U-B-L-E for your body and mind.

This may also extend to involuntary midnight movements, aka those pesky hypnagogic jerks.


Stimulants like caffeine and nicotine can make it hard to fall and stay asleep. This is because stimulants make your brain more alert and attentive to every sound or movement… and make that coveted deep sleep difficult to reach. This may also lead to hypnic jerks.

So while your morning coffee is just fine, try to hold back on that late-night Starbucks run to avoid sleep probs.


Alcohol is a depressant and can make you feel super sleepy. However, it can also wreak total havoc on your overall quality of sleep. This can make you more likely to experience hypnagogic jerks.

Unfortunately, there’s no proven treatment for hypnagogic jerks. But that’s OK — you don’t really need to treat them since they’re generally harmless.

But TBH, hypnic jerks can wreak havoc on your quality of sleep if they prevent you from falling asleep or waking up your partner on a regular basis. If you need some Zzz’s STAT, taking some preventative measures might help.

These prevention tips may help tame those nighttime twitches and give you back your precious deep sleep and REM sleep:

  • Ditch the caffeine (and other stimulants). Don’t panic: you don’t have to say no to coffee. But drinking less caffeine overall can help improve your overall quality of sleep — especially if you avoid caffeine in the late afternoon or at night.
  • Say “buh bye” to booze. Alcohol can often make you tired, but it can also mess with the quality of your sleep. Avoiding or reducing your alcohol intake can keep you from becoming vulnerable to hypnic jerks.
  • Work on when you work out. Exercise is good for your health, but a late-night sweat sesh that’s high intensity can affect your sleep — and not in a good way. Try to stick to morning or afternoon routines, and avoid working out after 8 p.m. if possible for a good night’s rest.
  • Breathe deep. Trouble getting relaxed or falling asleep? Breathing exercises can help. Try these breathing techniques to get yourself on the path to snooze-ville in no time.
  • Set a nightly ritual or routine. Establishing a pre-bedtime routine can set you up for sleepy-time success by helping you wind down and mentally and physically relax.

In most cases, hypnagogic jerks are not dangerous and don’t require medical attention. Mainly they’re just annoying if they keep preventing you from falling asleep.

But there are some (very rare) exceptions. Talk with your doc if you experience any of the following in addition to hypnic jerks:

  • multiple jerks during the day
  • other jerking or twitching movements during sleep
  • feelings of confusion when you wake up
  • tongue or mouth biting while you sleep
  • injury caused by hypnic jerks
  • wetting the bed

Hypnic jerks can also sometimes be confused with seizures. While they may seem similar, they have some key differences. Seizures are a serious occurrence that can be a result of an underlying condition or infection. Hypnagogic jerks, on the other hand, are benign phenomena that aren’t tied to any health conditions or concerns.

A hypnagogic jerk is an involuntary phenomenon that causes brief muscle contractions as you’re falling asleep. Experts aren’t sure what exactly causes these sudden jerks or jolts to happen, but they may be affected by factors like stress, anxiety, sleep deprivation, or evening caffeine intake.

While there’s no specific treatment for hypnic jerks, there are steps you can take to prevent them. Setting up a sleep routine, avoiding exercising or drinking caffeine too close to bedtime, and engaging in deep breathing relaxation techniques may help.