Ever woken up with the feeling you are falling?

Have you ever woken up with a sudden jolt just as you’ve started falling asleep? Maybe it felt like you were falling. Or that you were having a huge muscle spasm. You may have even felt a small shock sensation, or a bouncing feeling.

Perhaps it was even your partner that was experiencing it, and this in itself startled you back to consciousness.

It could be then, but not necessarily, that you are experiencing a hypnic jerk. You are certainly not alone though; it is estimated that around 70% of people may experience hypnic jerks at some point. I know I definitely have.

Different names

The world of sleep can be confusing, and there is no exception when it comes to the hypnic jerk, as it is also sometimes called to by one of the following names:

• Night starts

• Sleep starts

• Hypnagogic jerk – hypnagogic being a term used to describe the period of time when falling asleep or waking up

• Myoclonus, or myoclonic jerk – technically this is the medical term to describe an involuntary muscle twitch

So what is a hypnic jerk exactly?

A hypnic jerk is an involuntary twitching of a muscle, or muscles (the myoclonus as mentioned above). They usually occur just as you are falling asleep – referred to scientifically as the hypnagogic state of consciousness. This is why they are sometimes call hypnagogic jerks – because you most commonly experience them when falling asleep.

Note that hypnic is also a shortened version of the word ‘hypnagogic’. So you can see why there are all these possible expressions to describe the same thing.

When you experience a hypnic jerk it often causes you to wake up suddenly. When you wake up you may feel like you have just experienced, or are still experiencing, the sensation of falling, spasm, jolting or shock.

Note that the muscle twitching you experience also occurs in other situations. For example hiccups are also muscle twitches.

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That strange time of the night

It is during this phase of falling asleep that several unusual phenomenon may taken place. For example we discussed in a previous article the various sleep paralysis stories people have, which often come with bizarre or frightening hallucinations, or even out-of-body experiences.

Luckily there is nothing to be worried about – hypnic jerks along with these other phenomenon are not dangerous. They may be unsettling or frightening, but you do not need to fear going to sleep just because they may happen to you.

What causes the hypnic jerk?

So now you know that the hypnic jerk is a twitching of the muscles. But what causes the muscles to twitch?

As is often the case with the complex world of sleep, scientists are still not 100% certain about this. However, they do believe that the following factors can all contribute to hypnic jerks happening:

• Anxiety

• Stress

• Alcohol

• Caffeine

• Heavy exercise late in the evening

• Sleeping in an uncomfortable position

• Being very tired or fatigued

In addition to these factors which can contribute to the likelihood of a hypnic jerk occuring, there are 2 theories which try to explain why they occur:

1. The first theory is that they happen as a normal part of the nervous system relaxing and slowing down. For example your breathing slows down, temperature drops and your muscles relax. They are then thought to occur because of the muscle relaxation.

2. The second theory is that while relaxing as you fall asleep, your brain gets confused and thinks you are falling, so sends signals to the arms and legs to move to an upright position, resulting in the jerking sensation.

I have read viewpoints that the brain gets so confused it thinks the body is dying, or falling dangerously, and so wakes you with a jolt – but I personally don’t have much faith in that more extreme conclusion!

Make sure it is not another sleep disorder

If you are experiencing what you think are hypnic jerks, then for some people it could be something more serious like Apnea. If you have breathing difficulties when sleeping, or wake up not just with a jolt, but also with a gasp, croak or any other indicator that your breathing was affected, it may be wise to consult a medical professional to rule out Apnea.

A doctor would also be able to rule out the possibility of epilepsy, as a small number of people only experience seizures during the sleeping hours.

It is also possible that you may have restless leg syndrome, or periodic limb movement disorder, which again would be diagnosed by a medical professional or sleep expert.

And most rarely of all, is the possibility of exploding head syndrome, This sleep disorder is also harmless, and is characterized by a very loud noise in your head, which could sound like a bang or any other loud noise, and which wakes you up suddenly.

For the majority of people though, the hypnic jerk is a common and harmless phenomenon.

How can you prevent a hypnic jerk?

The hypnic jerk is such a common occurrence, that it may not be possible to prevent it happening completely. However, you can take steps to address some of the factors thought to increase the likelihood:

• You can cut down on alcohol and caffeine, especially in the 3-4 hours before going to bed at the least

• Try not to do heavy exercise late in the evening or night

• Ensure you are getting sufficient magnesium and calcium in your diet – this can help with muscle and nerve spasms

• Make sure you have a comfortable mattress and bedding, and that you sleep in a comfortable position, even with a partner. Personally I’ve found that I often experience a hypnic jerk when I am cuddling my partner to fall asleep, but not actually lying in the most comfortable position.

• If you are someone that suffers from anxiety or stress, then this is another issue to address altogether. However, you may find some useful advice on the section relaxation exercises for sleep. This provides practical short-term exercises, but also some ideas for more long-term techniques to tackle stress and anxiety.

• Try not to allow yourself to get too tired or fatigued. Obviously this depends on your particular circumstances, as some people understandably have very busy and tiring lives. But it may be up to you to try to give more importance to how much sleep you get. Have a read of the section on attitude towards sleep for some ideas about this.

Avoid the vicious cycle of worrying that you will experience a hypnic jerk

Hypnic jerks can become cyclical if you start worrying about them. This is a very common thing that happens with sleeping difficulties.

For example people who have insomnia will often start worrying that they won’t be able to get to sleep. This worrying then becomes the thing that causes their insomnia, even if the original cause (like noise or temperature) has long gone.

So in the same way, if you worry about hypnic jerks, then you may start to get less sleep and become more fatigued. Being fatigued is thought to contribute to the frequency of hypnic jerks, and so it is more likely you will experience them.

You now know that a hypnic jerk is not dangerous, and that many people experience them. So hopefully you can start to relax about them, and not go to bed thinking about them.

For more ideas about how to change your attitude towards sleep, and particularly falling asleep, have a read of a previous article ‘how to go to sleep instantly, or accept the fact that you can’t’.

What do you think about hypnic jerks?

There is not much research published about the hypnic jerk, mainly because it is thought to be harmless. So I am interested to know what your experience is. How often do you have them? What seems to make them worse or more frequent? What do you find helps to reduce them?

Please share your experiences in the comments box below and help out other readers with your ideas and theories.

Exploding head syndrome is a relatively uncommon sleep disorder. It falls under the category of parasomnias, which are most easily understood as strange occurrences that happen during sleep, or while falling asleep or waking up.

It was first documented in 1920 by the scientist Armstrong-Jones, who described it as a ‘snapping of the brain’.

It is mostly experienced by people over the age of 50, though some do experience it in childhood even.

The name ‘exploding head syndrome’ is misleading, as it conjures up all kinds of horror-film images. Fortunately though, people who experience this do wake up with their heads in one piece! To understand why it has such a dramatic name, we need to consider the symptoms:

Exploding head syndrome symptoms:

1. People who experience exploding head syndrome describe hearing a very loud and sudden sound in their head. It usually sounds like one of the following:

• The sound of a bomb
• The sound of gunshot
• A loud clash of cymbals
• The sound of a door slamming
• An extremely loud rushing sound
• People screaming or shouting
• An electrical buzzing sound
• Any other loud sound which cannot be described exactly

2. People do not usually report feeling pain with exploding head syndrome. They may describe it as painful initially, but then reveal it is just extremely loud. They may however be startled, scared or upset when it wakes them up from sleeping or napping.

3. Exploding head syndrome is sometimes accompanied by a sensation of a flashing light.

4. People may feel it affects their breathing – with a gasping of breath, or short lasting difficulty breathing.

5. People may experience a short-lasting episode of sleep paralysis, sometimes taking the form of a reported out-of-body experience.

6. An episode can last for just a few seconds, or even up to a few minutes. They usually occur when falling asleep, or when waking up, but not during the main stages of sleep.

The researcher J M Pearce conducted a detailed study of 50 patients with exploding head syndrome in 1989 to analyze what kinds of symptoms they experienced, which you can read here for further information.

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Causes of exploding head syndrome:

The causes of exploding head syndrome are still not properly understood unfortunately. Two theories that have been put forward are:

• Minor seizures in the temporal lobe
• Involuntary movements of parts of the ear, such as the tympanum (the ear drum), or the tensor tympani (the muscle involved in reducing sound – e.g. the sound of chewing food)

J M Pearce in his study was unsure as the likelihood of these explanations. He believed it would be better to class exploding head syndrome with other biological mechanisms that occur when falling asleep. This includes the muscular jerks that most people experience, known either as sleep starts, hypnic jerks, or nocturnal myoclonus.

More recently in 2010, the researchers Thorpy and Plazzi also wrote that they believe exploding head syndrome should be classified as a variant of sleep starts rather than under the category of parasomnias as it currently is.

Treatment:

1. Visiting a doctor is an important first step. Many people feel embarrassed to talk to someone about this due to the strange symptoms they experience. A doctor though will be able to reassure you that it is harmless, and possibly prescribe medication such as clomipramine, which is a tricyclic anti-depressant.

2. Stress is known to be a factor that can increase the frequency and intensity of parasomnias and sleep starts. If you do suffer from stress and need to learn how to relax better, then read our extensive article on relaxation techniques for sleep. You might also want to try an acupressure mat which can reduce stress dramatically and help you fall asleep.

3. Do not allow yourself to become too fatigued. Tiredness is also known to contribute to these kind of sleep problems. So try to keep to a stable sleep schedule. We have plenty of good advice for you here at No Sleepless Nights to help you sleep better. You can always start with our section on good sleep hygiene.

4. It is important to not allow yourself to become anxious about falling asleep, worrying that you will experience exploding head syndrome and that something bad will happen to you. Whilst it is understandably quite disturbing, it is not known to have any damaging effect on you.