Hypnagogic Jerk: The Cause Of Twitching in Sleep

March 19, 2021
Hypnagogic Jerk: The Cause Of Twitching in Sleep

Have you ever lied down in bed, just about to drift off into blissful nocturnal sleep when suddenly your body jerks you awake? Unforeseen, you’re startled by this involuntary twitching while feeling your heart racing. If you’ve found yourself in this situation before, rest assured that you’re not the only one. You’ve fallen victim to a natural phenomenon known as a hypnagogic jerk or a sleep twitch.

Hypnic jerking is nothing more than an involuntary twitch that usually happens just as you are about to step into dreamland. Let’s dive further into understanding the science behind hypnagogic jerk.


The phenomenon is named in reference to the hypnagogic state – the transitional period between wakefulness and sleep. A hypnagogic jerk is a sudden and strong involuntary twitch or muscle contraction also known as myoclonus. These involuntary twitches occur while an individual is beginning to fall asleep. The same phenomenon is called a hypnic jerk if it occurs upon awakening. Both are often known as sleep start which may affect only part of the body, like an arm or leg. It may more commonly seem to cause the entire body to jolt suddenly.


According to an article published in the Journal of Sleep Medicine, hypnic jerks are quite common, with up to 70% of people of all ages and genders experiencing them. They seem to appear more frequently in childhood, often being mistaken for seizures and epilepsy. While little is known about their cause in adults, some prevailing theories include:

  • Anxiety and stress: Anxious thoughts or stress and worry may keep your brain active, even as your muscles try to relax as you drift off to sleep. This might cause your brain to send out “alert” signals as you doze off or even while you sleep. 
  • Stimulants: Caffeine and nicotine can impact your body’s ability to fall asleep naturally and stay asleep. Chemicals in these products may prevent your brain from reaching deep sleep and instead startle your brain from time to time. 
  • Exercise: Daily physical activity can help you get better shut-eye, but exercise that’s too close to bedtime may make you more likely to experience sleep starts. Your brain and muscles may not be able to slow down for sleep quickly enough. 
  • Sleep Deprivation: Sleep disturbances and poor sleep habits may be linked to hypnagogic jerks. 

Sometimes these awakenings can be provoked by another sleep disorder, most commonly disrupted breathing like sleep apnea. In addition, movements in sleep can sometimes suggest seizures. It may be necessary to have a diagnostic sleep study called a polysomnogram.

Fun Fact: Recent research suggests the origins of this sleep phenomenon date back to our evolutionary ancestors. The proposed theory is that hypnagogic jerks were a way to help earlier primates readjust their sleep positions before dozing off so they didn’t fall out of a tree or get hurt during their slumber.


It is important to understand that hypnagogic jerks aren’t a disorder. For that reason, symptoms of this condition aren’t signs of a problem. They are simply things you may experience. Symptoms of a hypnagogic jerk include:

  • Jerks or jolts of a muscle or body part
  • Falling sensation 
  • Sensory flash
  • Dream or hallucination that leads to startle, jump, or fall 
  • Quickened breathing 
  • Rapid heartbeat 
  • Sweating  


Hypnagogic jerks don’t require treatment. They are not a serious condition, and they won’t cause complications. Instead, treatment for hypnic jerks focuses on preventing them from happening. These steps may help you fall asleep and stay asleep without the interruption from sleep starts:

  • Avoid caffeine: A morning cup of joe is okay, but anything after midday may set you up for sleep disturbances. Try to reduce your overall caffeine consumption level, especially in the late afternoon and evening.
  • Avoid stimulants: In addition to caffeine, you should limit the amount of nicotine and alcohol you use in a day, especially after midday. A glass of Cabernet Sauvignon before bed may help you doze off, but you’ll be more likely to have a restless sleep.
  • Early Exercise: Get your daily sweat session in before noon. If you can’t swing that, try to do only low-intensity forms of exercise in the evenings.
  • Create a pre-sleep routine: For 30 minutes before bedtime, disconnect from technology, turn down the lights, and slow down. Help your brain prepare for sleep by cranking down your energy use and relaxing before you try to get a shut-eye. 
  • Breathing exercises: This can help slow your heart rate, brain, and breathing.


About 60-70% of people recall experiencing hypnagogic jerks. Therefore, it is important to remember that hypnic jerks are common. Experiencing them does not mean that a person has an underlying medical condition. Certain lifestyle changes may help people reduce the number of hypnic jerks that they experience. Anyone who is experiencing hypnic jerks regularly and is concerned about their overall health or sleep quality should seek the advice of their doctor. 

Have you encountered any vivid experiences attributed to hypnic jerking? What are your thoughts about sleep twitches? Please leave your comments below!

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