Hypnic Jerk: Twitching in Your Sleep Explained

Written by Jill Zwarensteyn, Editor

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In This Article

What is hypnic jerking (or a sleep twitch)? Our sleep experts explain this very normal movement.

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Have you ever been lying down in bed, just about to drift off to sleep when suddenly your body jerks you awake? Out of the blue, you’re startled by this involuntary twitching, and you can feel your heart racing. If you’ve found yourself in this situation before, rest assured that you’re not the only one, and this twitch is more common than you might think. This phenomenon is called a hypnic jerk or a sleep twitch. 

Hypnagogic jerking¹ refers to involuntary muscle contractions that cause sudden and brief twitches or “jumps” when you’re trying to fall asleep. The word “hypnagogic” describes the transitional period as you are falling asleep; a state between being awake and being asleep. These startling, involuntary jerks of the muscles occur during this time and can easily disrupt bedtime, leaving you feeling wide awake.¹ 

Some people experiencing these jerks may lash out or move their legs and arms, while others might jump or twitch ever so slightly. Occasionally people shout or yell² when it happens, and other times, people aren’t even aware that it occurs unless a partner tells them the next day. 

Hypnic jerks are a type of myoclonus or myoclonic jerk³, which is a quick jerking movement that you can’t control. Other examples of myoclonus jerks include hiccups or certain symptoms of nervous system disorders like seizures from epilepsy.³

Different Names for Hypnic Jerking

As mentioned, hypnic jerks are also commonly known as hypnagogic jerks⁴, referring to the time between being awake and falling asleep. They are also called sleep starts.² While there may be a few different names for them, each name refers to the same phenomenon.

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Symptoms of

Hypnagogic Jerking

The most common symptom of a hypnic jerk is a sudden, involuntary jerking of the muscles– usually in the arms or legs.¹ The sleeper may or may not wake up from this jerk or be aware of it.²

Other common symptoms that can accompany this involuntary “jumping” of the muscles include¹:

• A feeling of falling
• Waking up feeling startled or anxious
• Rapid heart rate
• Accelerated breathing
• A sensory flash
• Hypnagogic hallucination

Hypnagogic hallucinations⁵ are visual images or very short dreams that occur as you’re just drifting off to sleep. Sometimes these hallucinations are more than visual; they can also be auditory or somatic, where you hear something that’s not there or feel something that’s not there.⁵

What Causes Hypnic Jerks?

According to the American Academy of Sleep Medicine, hypnic jerks are quite common, with up to 70 percent of people of all ages experiencing them at some point in their life.² 

Adults are more likely to complain of frequent or intense jerks compared to children, and while they are a common occurrence, certain risk factors increase your risk for experiencing hypnic jerks²: 

• Poor sleep habits – Irregular sleep schedules, chronic sleep loss, and frequently interrupted slumber may contribute to involuntary twitches.
• Stimulants – Caffeine, nicotine, and certain drugs can impact the body and brain, making these movements more likely.
• Late exercise – While exercise is important for the body, working out too close to bedtime can have a stimulating effect on the brain, leading to twitching.
• Anxiety – Stress and worries can also stimulate the brain, making it difficult to wind down for sleep, which may increase the likelihood of hypnic jerking. 

There are some interesting theories as to why we experience hypnic jerks at all, aside from outside factors like caffeine, stress, or exercise. For example, some experts⁶ believe it is an evolutionary byproduct from our ancestors’ earliest days. They say that if our bodies began to relax into sleep, we might experience a sudden jolt to prevent us from fully relaxing and falling from the safety of the tree in which we were resting.

Others theorize⁷ that sleep starts are a way for our body to test whether or not sleep paralysis has yet taken effect. 

When we go into REM sleep, our body goes into “sleep paralysis” in order to prevent us from acting out our dreams. The theory is that hypnic jerks might be the brain sending electrical signals to test the muscles for this paralysis, a bit too early, before the sleeper has gone into REM sleep.⁷ 

Whatever the reason behind hypnic jerks, they can be an unpleasant disruption to sleep. Luckily, there are some ways to prevent them or lessen their frequency.

Tips to Stop Hypnic Jerks

Reduce Caffeine

According to research, excessive caffeine intake⁸ can increase the likelihood of hypnic jerks. Furthermore, caffeine can remain in your system up to six hours⁹ before bedtime. 

Since the stimulating effects of caffeine can lead to hypnic jerks and make it harder to fall asleep, the best thing to do is to cut back on your caffeine consumption and avoid caffeine up to six hours before you go to bed. That means if your bedtime is 10:00 p.m., you shouldn’t consume caffeine after 4:00 p.m.

Read More: Caffeine and Sleep

Exercise

Exercise¹⁰ is vital for your physical and mental health, not to mention your sleep. If you aren’t already, you should be getting at least 150 minutes of moderate physical activity¹¹ and two days of muscle-strengthening exercise per week. 

However, there are appropriate times of the day when you should be exercising. Research shows that vigorous exercise in the hour before bedtime¹² is likely to disrupt sleep. This disrupted sleep can then increase the likelihood of hypnic jerks.² 

Instead of exercising just before bed, try moving your workout earlier in the day. Give yourself a few hours between an elevated heart rate and lying down to sleep, and see if that helps.

Relaxing Herbs

Different herbs and essential oils may help induce a deeper and more relaxed sleep, possibly reducing your risk of hypnic jerks. Lavender¹³, for example, has been shown to reduce anxiety and induce sleepiness when inhaled. When ingested, valerian root¹⁴ could also improve sleep quality.

Find Out More: Pillow Mists & Sprays: Do They Really Help You Sleep?

Unplug

Blue light¹⁵ emitted from screens like cell phones, T.V.s, tablets, and computers can make it harder to fall asleep by obstructing your body’s natural melatonin production, making you feel less sleepy at bedtime. We recommend giving yourself at least one hour before bed with no screens so that your body will naturally get sleepy. If you can’t do an hour, then at least give yourself 30 minutes without screen time.

During this time, you can do things that relax you, such as reading a book, meditating, journaling, or taking a warm bath.

Learn More: How Technology Impacts Sleep Quality

Supplements

Magnesium is something to consider if you have hypnic jerks because it is associated with muscle relaxation¹⁶. Additionally, experts say that many people don’t get enough magnesium¹⁷ from diet alone, so supplementing before bed is not a bad idea.

Read More: Best Magnesium Supplement

Melatonin is another common sleep aid that may help you fall asleep more easily, which potentially could reduce the likelihood of hypnic jerks. However, if you are taking any medication, are pregnant, or have any health issues, we recommend consulting with your doctor before taking any supplements.

Read More: Best Melatonin Supplement

View Our Comparison: Magnesium vs. Melatonin