Hypnic Jerks: The Falling Feeling That Jolts You From Your Sleep

You are snuggled up in bed, relaxed and just starting to fall asleep, when all of a sudden…

You jolt awake!

You leap upright. Your muscles are tense. Your heart is racing. You are gasping for air. All because it feels like you fell off your cliff.

Once you calm down, you take in your surroundings. You are safe and sound in your bedroom. You lay your head back on your comfy pillow and think to yourself:

What was THAT!?

It’s very likely you just experienced a hypnic jerk.

A what?

Even if you don’t know what a hypnic jerk is, chances are that you have had one at some point in your life.

To some it feels like your whole body shakes, to others it feels like an electric shock. Some people have even described the sensation as though you are falling or bouncing.

Don’t worry, you are not alone. It is estimated that around 70% of people will experience hypnic jerks at some point in their life.¹ I know I have.

So let’s take a closer look at hypnic jerks, to get you up to speed on this unusual bedtime phenomenon.

What is a Hypnic Jerk?

A hypnic jerk is an uncontrollable twitching of one or more muscles. Most people experience hypnic jerks just as they are dozing off.

As an outsider looking in, it is easy to identify a hypnic jerk, it will resemble a quick and sudden jolt. Imagine how someone reacts when they accidentally put their hand on a hot stove. The movement is an instant jolt away from the stove, without thought. The entire movement is over in the blink of an eye. A hypnic jerk is similar, lasting less than a second.

As to why they are called hypnic jerks, the answer becomes apparent when you break the word down:

Hypnic: Inducing sleep

Jerk: A quick sudden, sharp movement

Smoosh the two together and you get the very fitting Hypnic Jerk.

Fun fact: Your hypnic jerk is unique to you. Some people experience these involuntary movements in their legs or arms while others report that their whole body spasms.

Other names for a Hypnic Jerk

It is likely you have heard of hypnic jerks before, but perhaps under a different name. Common names for hypnic jerks include:

• Night starts
• Sleep Starts
• Sleep Twitches
• Sleep Jerks
• Sleep Spasms
• Sleep Jump
• Body Jerks
• Hypnagogic jerk

If you have discussed hypnic jerks with your doctor, it is likely you would have also heard it referred to by it’s medical name, Myoclonus or Myoclonic Jerks.²

Who is most at risk of Hypnic Jerks?

According to a study on sleep disturbances in the journal of Neural Transmission, the number of hypnic jerks you will experience at night is determined by your age.

Children under 12 experienced on average 4-7 hypnic jerks per hour decreasing down to 1-2 per hour at 65-80 years old.³

How do you know you have experienced a Hypnic Jerk?

Being jolted from your sleep can be scary and confusing. While you lay in bed disorientated it can be difficult to determine what exactly just happened.

Below are some common symptoms associated with hypnic jerks. You may experience one or more of these symptoms following a hypnic jerk.

1. Falling sensation – When laying in bed you experience a sensation similar to that as if your whole body is dropping through the air, some say it’s like tripping while others say it’s like leaning too far back in your office chair. Despite your body actually resting on the mattress you will feel completely unsupported, similar to how you feel during a trust fall.

2. Bouncing sensation – You feel like your whole body has bounced up of the floor.

3. Shock – You awake feeling traumatized and helpless

4. Racing heartbeat – Your heart rate spikes, as if you are waking up from a nightmare.

5. Sweats – You suddenly sweat and your skin feels clammy.

6. Sensory Hallucinations – briefly see and feel images, it might be the feeling of sand in your hands, the image of a building or even hearing a bird call before being jolted into consciousness.

7. Hypnagogic Dream – A dream that is experienced in stage 1 of sleep, just as your body is transitioning between being awake and asleep.

9. Mouth noise – You make a short noise out of your open mouth. It could be a sharp inhale of air, a short moan, grumble, croak or something even more unusual.

Because a hypnic jerk only lasts a fraction of a second, the above sensations will be over before you know it. Coupled with the sheer surprise of being jolted from your sleep, the fact that these symptoms are similar to other sleep disorders, identifying what just startled you awake can prove difficult.

Interestingly, some people do not even wake up after experiencing a hypnic jerk. If you share a bed your partner may have noticed you twitching as you fall asleep. This often makes for an unusual conversation the next morning when your partner mentions your body spasms but you do not recall them.

Don’t misdiagnose it!

Here is where it gets tricky. Because a hypnic jerk can leave you in shock, it can be difficult to determine what just woke you up.

Was it the obnoxiously loud horn from a passing car?

Was it a nightmare?

Was it a similarly bizarre sleep experience like sleep apnea, restless leg syndrome or exploding head syndrome?

Or was it the shaking sensation from a hypnic jerk?

In your traumatized state it really can be hard to recall the symptoms listed above.

If you share your bed with your partner you can enlist their help. Ask them if they have noticed you twitching. It may even be the case that your jerking movements have woken them up and they have been too polite to mention it.

Failing this you will have to turn to the professionals. A trip to the sleep doctor is in order. The most likely recommendation will be a polysonogram. Don’t worry; while it may sound scary, it’s just a simple sleep study.

Participating in a sleep study is so easy you can do it with your eyes closed. Literally. Essentially you will be required to sleep in a chamber while a doctor monitors your body functions. Data will be recorded such as your brain waves, heart rate, movements and breathing. From the data the doctor will be able to identify any abnormalities that may be responsible for your hypnic jerks.

And before we continue…This is not a hypnic jerk!

You know that weird feeling when you drift off while sitting upright and your head jolts up suddenly? It has likely happened while watching a move from the comfort of your couch.

You may be relieved to learn that this is not a hypnic jerk.

While it might have a similar feeling, this jerky motion is actually a natural survival mechanism.

Your head weighs 11 pounds. As you snooze while seated, your head will fall forward. If it falls too far it bend your air pip, making it difficult to breath.

Here is where your brain kicks in, jolting your head upright so that you can properly breath. This head nod is your bodies way of looking out for yourself and is no cause for concern.

What Causes Hypnic Jerks?

Here is where things get spooky. No one knows exactly what causes hypnic jerks. Yup, even though 70% of people will experience hypnic jerks in their lifetime, there is no conclusive information currently available as to what causes them.

That said, there are it is widely believed that the following factors can all contribute to hypnic jerks:

1. Anxiety – It’s likely that if you have anxiety than hypnic jerks are the least of your sleep problems. Anxiety has been linked to many sleep disrupting ailments, from insomnia to decreased sleep length. If you want good sleep in general, you are going to have to treat your anxiety.

2. Stress – Acute or long term stress can alter the brains natural ability to transition from awake to asleep at night. Worrying while your brain is trying to slow down may increase the occurrence of hypnic jerks. Like anxiety, stress can negatively impact all areas of sleep and will require treatment for proper rest.

3.Caffeine – Found in coffee, chocolate and many other commonly consumed foods, caffeine is a major sleep disruptor. Drinking caffeine in the afternoon may disrupt your circadian rhythm, which could result in a greater chance of hypnic jerks from occurring.⁴

4. Drugs and alcohol – Drugs and alcohol it is commonly known that drugs and alcohol change how your brain processes signals. The disrupted brain activity as you fall asleep may result in muscle twitching. Alcohol in particular has been linked to an increase in hypnic jerks.⁵

5. Dietary deficiency – A shortage of magnesium, calcium or iron in your diet may lead to an increase in hypnic jerks.

6. Exercise – Intense physical activity too close to bedtime can cause both physical and mental exhaustion, leading to decreased energy stores and changes in brain activity. This change in brain state combined with “primed” muscles from the earlier exercise may lead to hypnic jerks as your brain winds down for the night.⁶

7.Medication – Prescription medicine such as anti-depressants or pain meds can alter brain activity. In it’s altered state the brain may send mixed messages as it transitions from consciousness to unconsciousness, resulting in uncontrollable jerking movements.

8. Brain lesions – Brain lesions come on from disease or injury and are identified a CT or MRI scan. But not all brain lesions cause hypnic jerks, just those on the pyramidal tract of the brain. Research indicates that lesions to this area may result in jerky movements as you fall asleep.⁷

9. Sleep disorders – Your unrelated sleeping disorder may also be responsible for your nighttime twitching. Let’s take narcolepsy for instance. Individuals suffering from narcolepsy are more likely to experience other sleep related sensations such as hallucinations or sleep paralysis than those without. Sleep disorders may contribute to irregular brain activity which can lead to hypnic jerks as you fall asleep.

10. Sleep variables – as broad as it may be, your unique sleep variables may be responsible for your body spasms. Factors like sleep position, schedule, amount of sleep and more may all combine to become the perfect recipe for hypnic jerks.

In addition to this there are a number of theories as to why hypnic jerks occur.

Theory 1: It’s your body slooooooowing down

While drifting off to sleep may seem like a simple process, there is a lot going on behind the scenes. Your entire nervous system will begin to relax and slow down: Your breathing and heart rate will slow down, your body temperature will drop and your muscle tone shifts. During this process it is thought that nerves can misfire, resulting in sudden and unexpected tensing of the muscles.⁸

Theory 2: You’re literally falling asleep

As you fall asleep your brain confuses the relaxing of your muscles as a sign that you are actually falling though the air. In preparation for the landing, your brain tells the muscles to tense up, to protect you from harm. This sudden tensing is the hypnic Jerk.⁹

Theory 3: Blame your ancestors

Creationist? You can skip this theory. It is possible that hypnic jerks were an unnecessary evolution trait that was passed down from our ancestors. It is speculated that hypnic jerks may have been used as a warning by the brain to check for nearby predators.

Like I said, these are all just theories. More scientific study is needed to help narrow down the exact cause of hypnic jerks.

How to treat Hypnic Jerks

Because the cause of hypnic jerks varies from person to person, so will the cure. As you might have guessed, a lot of curing hypnic jerks comes down to trial and error. Finding the solution will require perseverance.

As a result, many people choose to simply accept that hypnic jerks are a harmless part of their life. And in all but the most unusual of circumstances your pre-sleep body spasms are just that. Harmless.

The best thing to do after experiencing a hypnic jerk is to calm yourself down and to not worry about it. Worrying just makes it more difficult to fall asleep.

According to Marianne Middleton, clinical coordinator at the Lawrence Memorial Hospital Sleep Disorders Center, hypnic jerks can sometimes lead to a cycle of chronic insomnia.¹⁰.

If you lose sleep because you constantly jerk awake, you will become fatigued and may develop anxiety or worry about falling asleep. The more worried and tired you are, the more likely you are to jerk awake. The more you jerk awake, the more sleep you lose.

So the first thing to do after experiencing a hypnic jerk is to take a deep breath, relax and not give it another thought.

If you are desperate to rid yourself of hypnic jerks then the first thing you should do is eliminate the causes I listed above.

To summarize:

• Cure your anxiety and stress. At the very least get it to a manageable level.
• Avoid caffeine, drugs and alcohol in the afternoon.
• Alter your exercise routine.
• Tweak your sleep position, sleep schedule and practice good sleep hygiene.
• Consult your doctor as to whether or not your prescription medication could be contributing to hypnic jerks.
• Create a sleep diary and monitor your sleep efficiency.

Have you tried everything to prevent hypnic jerks and you still can’t fall asleep? Maybe it’s not the hypnic jerks but the anxiety about having them. Whatever the reason, if your sleep is being disrupted then it is time to turn to the medical professionals. There is no shame in consulting your doctor, sleepless nights can have a negative impact on all areas of your health.

Do you suffer from hypnic jerks? Have you made a lifestyle adjustment and accidentally found the cure to your night time muscle-flexing? Let me know in the comments below.