What Causes Hypnic Jerks… And Are They Dangerous?


You’re about to doze off into a deep, restful sleep… and then you suddenly wake up with a jolt. Does this sound familiar?

Alternatively, your sleep is interrupted by an incredibly realistic dream in which you fall off a cliff, and the bump when you “hit the ground” wakes you with a start, your heart pounding as your entire body spasms at once.

fall in sleep

What is this phenomenon?

Involuntary Jerks During Rest or Sleep

This involuntary twitch, which comes alongside the feeling that you are falling in your sleep, is called a hypnic jerk.

Though they can be startling, hypnic jerks are not harmful, nor are they a symptom of a negative health condition. They are a common phenomenon experienced by a majority of people on Earth!

Most people can even sleep through their hypnic jerks, though you may find yourself lying awake in the middle of the night, trying to figure out how to keep these sudden movements from waking you up so often.

Though researchers are still trying to completely understand this sleep disruption, numerous theories have been formed about its origins.

Scientists have identified multiple factors in your life that you can control in order to lessen your hypnic jerks or even keep them away completely; this includes how you think about stress, how much caffeine you take in, and what time of day you exercise.

If you’ve wondered lately, “Why do I twitch when I sleep?” or “How can I stop these falling dreams that wake me up?” you’re in the right place. Let’s get into the details.

What is a Hypnic Jerk?

A hypnic jerk, also known as a “sleep start” or “hypnogogic jerk,” is a sudden, brief, and strong contraction of your body which occurs just as you’re falling asleep.

The hypnic jerk is a completely involuntary twitch that can feel similar to the way your body “jumps” when you are startled. Hypnic jerks are very common, experienced by somewhere between 60 and 70 percent of all humans – mainly in children.

You may completely sleep through your hypnic jerks. However, some of these twitches are strong enough to wake you up. They may be accompanied by a dream in which you are falling, with the jerk at the end as you “hit the floor.”

You may also experience a quickened heartbeat, sweating, or a flash of sensory input, such as a bright light or loud sound.

Your hypnic jerks may keep you awake all night, or just briefly interrupt your sleep before allowing you to doze off once more.

What Causes Hypnic Jerks?

Researchers are still trying to understand this common phenomenon.

Healthy and unhealthy people alike experience hypnic jerks. However, after extensive studies, several theories have emerged about the causes behind this.

why do i twitch when i sleep

Rest Mode

One theory is that the jerks occur as your nervous system shifts into a resting mode for the night. As you fall asleep, your heart rate and breathing slow down, your body temperature drops, and at the same time, your muscle tone shifts.

As these changes occur, your body may jerk as a result of the transition between more active and resting states.


Another theory is that your body can mistake the sense of relaxation you feel as you doze off as a sign that you are falling. As a result, it “jerks” you awake so you can catch yourself.

In this way, your body is trying to protect you from a threat that does not exist – but it is good to know that you can trust your body to wake you up in case you’re truly falling off the bed!


A third theory is that hypnic jerks have an evolutionary basis. Your primate ancestors, as they spent the night in trees, were in danger of getting hurt if they fell from the tree and slept through the event.

Hypnic jerks may have been the body’s defense against falling, helping the primates adjust their resting positions as they relaxed into sleep, and waking them up the instant they felt they were beginning to fall.

Whichever theory is correct, it is clear that hypnic jerks are a sign that your body and mind are not completely passive elements when it comes to sleep.

You do not just “turn off” when you go to bed and “turn on” when you wake up later. Your brain and body are still operating while you sleep, trying to make sense of the world around you and allow you to confront external stimuli!

Some people experience stronger hypnic jerks than others, or experience this sleep disruption more frequently than others, depending on different aspects of their lives.

Other hypnic jerk causes may include things that are known to interrupt sleep. For example, excessive levels of anxiety, stress, and worrying may keep your brain and body active even as you try to relax for the night.

An anxious brain may remain on high alert and send you a “watch out!” signal as you begin to drop off, waking you up again. Also, the more your sleep is interrupted by hypnic jerks, the more you may experience anxiety or stress about getting enough sleep every night – which can make your hypnic jerks worse.

Stimulants such as alcohol, caffeine, and nicotine can negatively impact your body’s ability to both fall asleep in the first place, as well as to stay asleep throughout the night.

The chemicals in these substances stave off the deeper levels of sleep, occasionally “startling” your brain in the middle of the night, which can cause body-wide hypnic jerks. As such, your body is unable to relax fully and will be more prone to further disruptions.

This video goes into more explanation on the hypnic jerk.

What Does It Mean When You Fall in Your Sleep?

Often, hypnic jerks occur at the end of falling dreams that wake you up as you hit the ground. These dreams occur because of a fascinating process called dream incorporation.

Your brain is very good at creating stories that make sense of the world around us, especially while you are dreaming. During a dream, the parts of your brain which plan for and predict events are less active, allowing your mind to react more creatively to any input that it receives.

If you’ve ever dreamed about hearing someone play an annoying horn, and then realized once you woke up that the awful sound you heard was coming from your alarm clock the whole time, then you have experienced dream incorporation.

Your brain took in the sound of the alarm and provided an explanation for it in the form of someone playing an instrument.

Therefore, when your brain detects that your muscles are relaxing in a manner similar to when you are falling from a high distance, it provides you with an explanation in your dreams, giving you the experience of falling – which ends in the hypnic jerk.

You may dream that you have fallen off a cliff, jumped into a hole, or even just stepped sideways off of a sidewalk. In any of these cases, your brain is trying to make sense of your body’s sensation of falling and tells you a story that makes more sense than an apparently random motion.

Are Hypnic Jerks an Indicator of Something Bad?

The combination of the falling dream, the sudden jerking sensation, and the interruptions in sleep could make you think that hypnic jerks are a sign of a serious and negative health condition.

Some people experience alarming visual and auditory elements as well, such as seeing flashes of light or hearing a loud bang while they experience a hypnic jerk, which can be frightening.

However, hypnic jerks are not dangerous. They are not a sign of a negative neurological condition, though they can be mistaken for seizures.

Hypnic jerks are common and accepted by many people as a strange quirk. Although these jerks may be uncomfortable or alarming, they are a normal physiological event.

If you experience twitching when you sleep, or suddenly awake at the end of a dream in which you are falling, there’s no need for alarm. You can manage the effects!

hypnic jerk causes

Can They Disrupt Your Sleep?

Most people are able to sleep through their hypnic jerks. However, some of these jerks are strong enough to wake you up from an otherwise deep, restful sleep.

They can also keep you up all night with their frequency, or affect the sleep of someone else using the same bed if you startle them with the sudden movement.

If you are particularly concerned about these sleep interruptions keeping you from being well rested, you can call your doctor to make an appointment and discuss your concerns.

Your doctor may prescribe you some medications to help relax your muscles and allow you to sleep more easily. However, a doctor’s visit is not always necessary.

You may be able to alleviate your hypnic jerks with some simple, at-home solutions.

How to Reduce Twitching in Your Sleep

Though research is still being performed on the causes and effects of hypnic jerks, there are several activities known to reduce or even fully prevent the hypnic jerk.

As a bonus, they’re good for creating restful, refreshing sleep in general.

These solutions are minor adjustments to your daily routine, which will address some of the causes behind hypnic jerks that were discussed earlier.

Less Caffeine in the Afternoon

Reducing your overall intake of caffeine, especially during the afternoon and evening, can help you avoid twitching in your sleep.

A cup of coffee in the morning to help start your day is fine, but the stimulants in caffeine can affect your overnight sleep if taken too late in the day. Hypnic jerks are only one of many negative side effects.

hypnic jerk

Less Alcohol at Night

You may also find yourself experiencing more hypnic jerks if you drink a lot of alcohol. Alcohol is both a depressant and a stimulant, which makes for a difficult cocktail of chemicals for your body to process.

Though it might seem to initially relax you, a glass of wine or beer can negatively impact the overall quality of your sleep, jerking you awake throughout the night.

Better Timed Exercise

Most people accurately suggest adding exercise to your daily regimen to help you sleep through the night.

However, the time of day in which you exercise can make the difference between restful sleep and hypnic jerks.

Exercising in the afternoon or evening, right before bed, can get your brain and body into “wake up and be active” mode, which is counterproductive for a good night’s sleep.

Keep your physical activities to the earlier part of the day, in the mornings, if at all possible.

Creating a Low-Stress Environment

Anything that you can do to help relax and reduce anxiety during the day will also help you sleep through the night, without the rude awakenings of hypnic jerks.

You might find that various essential oils and herbs lull you to sleep with their pleasant aromas, calming your body’s twitching at the same time.

Creating an environment free of electronic stressors can help as well. At least a half an hour before you try to fall asleep, turn off your smartphone, TV, and laptop, and let your brain relax in the dark for a while.

The result will be a deeper state of sleep, free of twitching!

This video goes into more details on how to prevent falling in your sleep and get a better rest.

Acceptance – Relax!

Also, though it may seem counter-intuitive, the best thing you can do to help reduce the twitching that interrupts your sleep is to not worry about it.

Often times, your concern about lacking proper sleep can keep you awake with stress! Anxiety over not getting enough sleep is just as potent as any other kind of anxiety, especially when it comes to messing with your sleep cycle.

To prevent this, you can make a practice of telling yourself that it does not matter if you wake up in the middle of the night. As a result, you might find yourself sleeping all the way through!

Now that you understand hypnic jerks and the factors that cause them, you are well equipped to reduce how often you fall in sleep and then wake up with a jolt. Relax, watch your diet and exercise, and sleep well!

Have you had a hypnic jerk?

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