Why Do I Twitch When I Sleep and Should I Worry About It?

A man sitting on a bed, awakened by his right leg twitching.

Have you ever been suddenly woken up by your body involuntarily twitching or a sudden jerk of your limbs? If so, don’t fret.


These muscle spasms are referred to as hypnic jerks, hypnagogic jerks, sleep starts, sleep twitches or sleep myoclonus. And while they may seem alarming, they’re common and harmless, in most cases.


We wrote this article to explain what causes twitching in your sleep, how to prevent it and when it might be a cause for worry.


Let’s get started.

Key Takeaways

  • Hypnic jerks are normal, involuntary muscle movements that occur during light sleep and can affect sleep quality when they are frequent or disruptive.

  • While we have not pinpointed the exact cause of sleep twitching, potential contributing factors include brain misfires during sleep onset, sleep deprivation, stress and stimulants like caffeine and nicotine.

  • See a doctor when hypnic jerks become frequent, disrupt your sleep, occur with unusual symptoms, worsen with lifestyle changes, or lead to daytime fatigue, as they may then indicate underlying health issues.

  • To reduce the likelihood of sleep twitching, avoid stimulants and late-night workouts, practice good sleep hygiene and engage in relaxing activities before bed.

Table of Contents

What Are Hypnic Jerks?

Hypnic or hypnogogic jerks are involuntary muscle movements that happen as you’re falling asleep.


You’re jolted awake by the sensation of falling or experience sudden muscle jerks in one of your limbs. You may feel these movements on both sides of your body.


Hypnic jerks are a type of sleep myoclonus, an umbrella term for sudden, involuntary muscle contractions that occur during sleep. As we mentioned earlier, hypnic jerks are normal.


However, other forms of sleep myoclonus can be a side effect of certain medications. They can also be indicators of a sleep or neurological disorder.


Here’s how a hypnic jerk might feel:


  • Feeling like you’re tripping or falling

  • A muscle twitch (in your arms or legs)

  • A sensation of feeling jolted awake as if threatened

  • A spike in heartbeat

  • Gasping or exhaling sharply


Twitching in your sleep occurs during stage 1 non-REM sleep, the lightest stage of sleep. So do brief dreamlike sensations of falling and tripping — known as hypnagogic imagery — that sometimes accompany hypnic jerks.


Since dreams can affect sleep quality, what you are dreaming of (like falling, for example) could also cause your sudden jerk.

Why Does My Body Randomly Twitch While I’m Sleeping?

A woman holding a cigarette with a cup of coffee beside her on a table.

The exact cause of sleep twitching has yet to be determined. However, there are several theories. Let’s discuss some of them.

Your Brain Misfires During Sleep.

One theory suggests that as you're falling asleep, your brain and muscles temporarily miscommunicate, leading to a sudden jolt in your body.


Sleep Foundation says that hypnic jerks start in the part of the brain responsible for your “startle response.”(1)

You Have Sleep Deprivation.

According to the American Academy of Sleep Medicine, hypnic jerks may be brought on by sleep deprivation and occur in 60% to 70% of people.(2)


Hypnic jerks or sleep starts can occur when you’re sleep-deprived, causing your brain to become unstable as it facilitates your transition from wakefulness to sleep.


You may enter sleep too rapidly, resulting in some of your body’s systems shutting down quicker than others.


This inconsistency leads to muscle control signals firing at the wrong time, causing you to twitch in your sleep.

You Suffer From Stress and Anxiety.

You might experience hypnic jerks when you’re stressed and anxious, according to a study published in the National Library of Medicine.(3)


Stress and anxiety go hand in hand with insomnia, which causes sleep deprivation. As we mentioned earlier, being sleep deprived may lead to hypnic jerks.


Racing thoughts also make falling asleep difficult, disrupting your transition from sleep to wakefulness. This disruption may lead to hypnagogic jerks.


It’s also worth noting that twitching in your sleep may lead to a fear of sleep itself, known as sleep anxiety. If you can relate, it’s wise to contact a healthcare provider.

You Smoke Cigarettes.

According to PsychCentral, nicotine and caffeine (and other stimulants) can cause hypnic jerks.(4)


Yet another reason to kick the habit, smoking can cause twitching in your sleep. Nicotine triggers the release of dopamine and norepinephrine, which increase your heart rate and make you feel more alert.


An increased heart rate and alertness cause sleep fragmentation and delay sleep onset, which in turn, make it more likely for your motor signals to misfire as you transition from wakefulness to sleep.


The result? A higher likelihood of experiencing hypnogogic jerks.

Your Caffeine Intake Is Excessive.

Meanwhile, too much caffeine can also lead to hypnic jerks. Caffeine blocks adenosine receptors in your brain. Adenosine is a chemical that encourages sleepiness.


Like nicotine, caffeine can make falling asleep difficult and increase alertness, both of which lead to nighttime twitches.

You Engage in Vigorous Exercise Before Hitting the Sack.

That high-intensity workout too close to bedtime may be the culprit behind your hypnic jerks.


Exercising before bed can delay sleep onset and overstimulate your nervous system, potentially disrupting your sleep and increasing the likelihood of hypnagogic jerks.

Are Hypnic Jerks Normal?

The short answer? Yes, in most people, hypnic jerks are nothing to be concerned about.


You might not even notice when they occur. Some people only discover they’re experiencing hypnic jerks when a partner tells them.


The downside here is that the partner may inadvertently wake up due to sudden movements, noise (such as sharp exhalation or bumping the headboard), or the mattress moving.


Sure, if hypnogogic jerks happen occasionally, it shouldn’t pose a problem to the partner’s sleep quality. However, if they become frequent and intense, it could lead to sleep issues for the partner and impact the relationship.

When Should I Be Worried About Twitching in My Sleep?

A man holding his twitching arm while awake.

There are some instances where hypnic jerks may be a cause for concern. Here’s when you should think about getting medical advice:


  • Their intensity and frequency increase to the point that they interfere with your ability to drift off and stay asleep.

  • They’re accompanied by other symptoms, like odd movements, disorientation upon waking, biting your tongue and incontinence.

  • These may be indicators of other disorders, such as Restless Leg Syndrome (RLS) and Periodic Limb Movement Disorder (PLMD) or neurological conditions.

  • Speak to a doctor if your hypnic jerks occur when you are fully awake or asleep.

  • Hypnic jerks worsen after lifestyle changes, such as starting new medications (like stimulants or antidepressants) or withdrawing from substances like alcohol. Also, speak to your healthcare provider if sleep twitching worsens after a period of severe stress and anxiety.

  • When you start to experience daytime fatigue.


Consulting a doctor can help you identify the root cause of severe or worsening hypnogogic jerks and treat any underlying health conditions.

How to Prevent Twitching in Your Sleep

There are several ways to lessen your likelihood of twitching in your sleep. Here are a few to consider:


  • Avoid caffeine too close to bedtime and limit your overall intake.

  • If not abstaining altogether, reduce your nicotine consumption.

  • Avoid vigorous exercise too close to bedtime. Work out earlier in the day.

  • Establish good sleep habits, such as a consistent sleep-wake schedule and optimizing your bedroom for sleep by keeping it quiet, cool and dark. (A 100% blackout sleep mask helps if you can’t control the amount of light in your sleep space.)

  • Get enough sleep, which usually means 7 to 9 hours.

  • Incorporate relaxing activities into your bedtime routine, such as a warm bath, meditation, gentle stretching or deep breathing exercises.

  • With your doctor’s go-signal, incorporate foods rich in sleep-promoting melatonin and magnesium into your diet.

    You can also opt for supplements. (If you didn’t know, magnesium for sleep helps reduce stress and anxiety and relaxes the muscles, allowing you to fall asleep faster with fewer sleep interruptions.)

Conclusion

We hope this blog post answered your question: “Why do I twitch when I sleep?”


Remember that hypnic jerks that occur during the lightest sleep stage are common and usually harmless. While the exact cause of these sudden muscle movements has yet to be identified, several theories suggest that sleep deprivation, brain misfiring, and other factors contribute to their occurrence.


A person should consult their healthcare provider when hypnic jerks are accompanied by other unusual symptoms, such as disorientation and tongue biting, to rule out any underlying sleep disorders or neurological conditions.


Are sleep starts preventing you from getting a good night's sleep? The solutions might be as simple as reducing your nicotine and caffeine intake and maintaining good sleep hygiene habits.


If you have experienced twitching in your sleep, share your experience with other readers by commenting below.

Sources:  

(1) “Hypnic Jerk: Why You Twitch When You Sleep.” Sleep Foundation, www.sleepfoundation.org/parasomnias/hypnic-jerks. Accessed 23 May 2025.

(2) “Sleep Starts.” American Academy of Sleep Medicine, sleepeducation.org/sleep-disorders/sleep-starts/. Accessed 23 May 2025.

(3) “Hypnic Jerks, Major Depressive Disorder, and Antidepressant Use: A Possible Relationship.” National Library of Medicine, pmc.ncbi.nlm.nih.gov/articles/PMC10590197/. Accessed 27 May 2025.

(4) “Why Am I Twitching In My Sleep?” PsychCentral, psychcentral.com/health/twitching-in-sleep. Accessed 27 May 2025.


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