Exploding Head Syndrome – Harmless But Disturbing

cartoon of an explosion with the word "boom!"

Do you ever hear a sudden loud noise just as you’re falling asleep or waking up, maybe accompanied by a flash of light?

But then when you check your house or ask someone else, you find no possible source of the noise?

If so, it could be that you’ve experienced exploding head syndrome (EHS). The good news is that although it can be quite scary, it’s not believed to be physically harmful.

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

Compared to some other sleep disorders, there hasn’t been so much funding for research into EHS in the years since then. Scientists are starting to understand it better though, and the importance of educating people that it’s a benign experience.


How common is exploding head syndrome and who experiences it?

In 2014, researchers in Germany reviewed multiple cases and previous research, with some interesting findings:

  • They found that the average age of onset was 54.
  • More women reported having EHS than men.
  • The average frequency of attacks was between once a day and once a week.
  • The most common symptoms were noise, fear and sudden sensations of light.

Research shows that many young people experience it

In contrast to the research in Germany, researchers at Washington State University in 2015 discovered that many young people also experience EHS.

Their research also included some other interesting findings, such as:

  • 18% of the 211 undergraduates they interviewed had experienced it in their lifetime.
  • 16.60% had experienced it more than once.
  • They didn’t find that women had it more often than men.
  • It was found in 36.89% of people who had a diagnosis of isolated sleep paralysis.
  • 2.8% had clinically significant levels of distress or reduced ability to function.

2019 research finds even higher prevalence rates

In 2019, a team of researchers again looked at how common EHS is, finding much higher prevalence rates than the previous two pieces of research:

  • Out of 199 female undergraduates, 37.19% had experienced it in their lifetime. 6.54% had it at least once a month.
  • Out of 1683 male and female adult participants in a separate study, they found a lifetime prevalence of 29.59%. And 3.89% had monthly episodes.

The team also found associations with other sleep disturbances, such as insomnia, sleep paralysis and nightmares.

2020 research sheds more light

In 2020, a fascinating study into EHS was conducted in a collaboration between the British Broadcasting Company (BBC) and psychologists in the United States and the United Kingdom.

In a survey of 6686 adults, 3286 reported that they had experienced EHS during their lives. 2954 said they had never had EHS.

Interestingly, 446 additional people reported having it, but were excluded due to the likelihood it was a different medical condition or because they reported significant pain during their episodes, which is not typically a diagnostic symptom of EHS.

Of the people who said they did have EHS, 5% said they had it several times a week. 35% had it several times a year, and 40% several times in their lifetime.

And in line with the German study, they also found that women were marginally more likely to have it than men.

It doesn’t cause physical harm

The name exploding head syndrome itself sounds very dramatic, provoking all kinds of violent images in the mind when wondering what the consequences of an episode might be!

The reality is that EHS is seen by organizations such as the American Sleep Association as benign and not associated with pain. However, it can cause a great deal of fear, anxiety and confusion, along with physical symptoms like increased heart rate.


Exploding head syndrome symptoms

There are several possible symptoms commonly reported. They can occur either when falling asleep or waking up.

1. Hearing a sudden and loud noise that isn’t real

The main symptom of EHS is hearing or feeling a loud and sudden sound. It can feel like it’s coming from inside your head, somewhere in your house, or even outside.

The type of sound varies between people, and might include:

  • The sound of an exploding bomb.
  • The sound of a gunshot.
  • A loud clash of cymbals.
  • The sound of a door slamming.
  • A rushing sound.
  • People screaming or shouting.
  • An electrical buzzing sound.
  • Any other loud sound which can’t be described exactly.

2. Seeing a flash of light

EHS is sometimes accompanied by a sensation of a flashing light. Like the noise though, there’s no actual light source causing it.

picture representing a flash of light

3. Fear and distress

Most people don’t usually report feeling pain with EHS. They may describe it as painful initially, but then reveal it’s just extremely loud.

However, the sudden noise and other symptoms can be very disturbing. So it’s not uncommon to wake up feeling scared or upset by what just happened.

In the BBC collaboration study in 2020, for example, 44.4% of participants reported feeling significant fear during episodes. Interestingly, a smaller number of 25% reported clinically significant distress.

Japanese researchers published a case study in 2021 of a woman who had repeated panic attacks that were caused by episodes of exploding head syndrome. Interestingly, they discuss their belief that EHS can be “relieved only through patient education and reassurance.”

4. Elevated heart rate and breathing

Brian Sharpless Ph.D., who has published several papers on EHS, described in his 2018 research the most common symptoms as:

  • Tachycardia
  • Fear
  • Muscle twitches
  • Respiration difficulty

Interestingly, he also found that visual phenomena were reported by 27% of people with EHS – a figure he described as “more common than expected”.

5. Accompanying sleep paralysis

As the research at Washington State University found, EHS is sometimes accompanied by sleep paralysis.

Sleep paralysis itself can also be very frightening, so it’s unsurprising that a combination of the two sleep disturbances can cause distress.

6. Worse sleep?

The 2020 study by the BBC also found interesting effects on people’s sleep in general. They found people with EHS typically took longer to fall asleep, had shorter sleep duration, and worse sleep efficiency.

However, they do note that the differences were not clinically meaningful. I’ve added it here under the symptoms as I think it was interesting that it came up in the study, but it’s not listed as a symptom in sleep disorder guidelines.

Reader EHS poll

I ran a poll of readers for three months to see how often they felt they experienced EHS.

Out of 7,752 readers who voted, a combined total of 53.5% said they experience it at least once a month. 41.9% said they experience it very rarely.

These numbers should be taken with a pinch of salt though, as I only polled readers of this article. So rather than a random sample, it’s people who were probably inspired by their experiences to look it up online.

chart showing the results of a poll about how often readers experience exploding head syndrome

Causes of exploding head syndrome

The causes of exploding head syndrome still aren’t properly understood. Several theories have been proposed:

  • A neurological condition, such as minor seizures in the temporal lobe.
  • A sudden movement in inner ear parts, such as the tympanum (the eardrum), or the tensor tympani (the muscle involved in reducing sound – e.g. the sound of chewing food).
  • Related to fear, stress or anxiety.
  • Calcium signaling impairment.

In 2010, the researchers Thorpy and Plazzi suggested that EHS might be a form of hypnic jerks, saying:

The EHS is a benign, usually self-limited, condition that is likely a sensory variant of the hypnic jerk. No testing or medications are necessary when the history is typical. Education and reassurance are the cornerstones of therapy. If the symptoms occur multiple times a night and cause insomnia, a hypnotic may be useful.

Going back to the 2020 BBC study again, they asked the participants what they believed caused their EHS. Here are the main causes reported and the percentage of people that mentioned them:

  • Something in the brain – 60.6%
  • Stress – 34.7%
  • Medication side effects – 7.2%
  • Something supernatural – 2.8%
  • Electronic equipment – 2.3%

Treatment

The treatment options for EHS are limited due to the fact that it’s seen as physically harmless, and still not fully understood.

Knowing that it has a name, that you’re not alone in experiencing it, and that it’s not dangerous might be reassuring enough for many people.

However, you might like to consider the following options if you remain concerned:

1. Talk to your primary care provider

Speak to your doctor or physician if you’re concerned by your symptoms and they are causing you distress or loss of sleep.

They might check for other causes, such as headache disorders or seizures. They can also help reassure you that it’s harmless.

2. Medication

There’s isn’t a standard pharmaceutical treatment for EHS. This would be something to discuss with your doctor, who might consider a drug treatment tailored to your specific medical history and symptoms.

3. Reduce stress and anxiety

Stress and anxiety can increase the frequency and intensity of some sleep disorders. If you’re under a lot of stress and/or suffer from anxiety at night, it’s a good idea to find ways to tackle it.

Some good ways to tackle stress include exercise, walking, yoga, tai-chi, meditation, mindfulness, or simple breathing exercises in bed.

Here’s a simple breathing exercise I find calming that you could try in bed if you’re feeling anxious about sleep.

Breathe in through your nose for the count of four and then exhale through your mouth for the count of six. The exact count isn’t so important, as it will depend on your lung capacity and counting speed – do what’s comfortable for you.

What’s interesting is to make the exhale longer than the inhale, and to try to breathe in while expanding your belly rather than just your chest. Try it to see if you find it calming too.

4. Practice good sleep habits

Sleep deprivation, exhaustion, and many lifestyle choices can increase the likelihood of disturbed sleep. Try to stick to a regular sleep schedule, and practice good sleep hygiene.

5. Try not to worry about your sleep

It’s important not to become anxious about falling asleep. Try not to worry that you’ll experience another episode or that something bad will happen to you.

That might be easier said than done, but some positive self-suggestion at night can be helpful.

Prevention strategies reported by people with EHS

One final look at the results of the 2020 study reveals some interesting possible techniques to cope with EHS.

The study participants were asked what prevention strategies work for them, and how effective they thought they were.

Here are the top methods that people say helped them:

  • Using or refraining from substances, such as drinking alcohol before bed or taking sleeping pills. It’s not clear in the published study whether more people had success taking or stopping taking substances. It looks to me like drinking alcohol has a positive effect on reducing EHS, but I can’t be sure from the way the data was published!
  • Don’t lie on your back.
  • Got to bed earlier and get enough sleep.
  • Practice mindfulness techniques/relaxation exercises.
  • Get up for a short while if it happens, and then try to sleep again later.
  • Try to wake yourself up during an episode.

Your thoughts

Have you experienced exploding head syndrome? What symptoms did you have, and how did it make you feel?

Feel free to share your story and thoughts in the comments below.

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  1. I have just woken up to what sounded like a gun shot and glass smashing. Scared the life out of me. I can’t go back to sleep it’s nearly 3 am. Woke and my heart was racing and literally jumped out of sleep. Now googling what could be wrong with me.

  2. About three years ago, during a stressful time, at night when nearly asleep I started hearing an extremely loud noise that sounded external and internal. I can only describe it as a split second of an orchestra playing the finale at a concert. Sometimes it would happen once and others multiple times at night. My boyfriend at the time was staying over and I kept jumping out of my skin. I tried to explain and he said there were no noises. This went on for some time and then seemed to go. It happened a few times since but not like that bout. Only just found an explanation.

    To note I’ve previously experienced sleep paralysis once and eye twitching during times of stress. The noise with this was different from the noise that I experienced with sleep paralysis in that with that, it sounded like being in a large hall full of talking people.

  3. In the last six months, I have started “hearing” a sound in my head. I can pinpoint the location to be a diagonal section of my brain from about the front middle of my head to the back right. When it happens, my whole body feels it….like if you were standing in front of a giant speaker and someone played a loud bass note. It happens two or three times a month. I have various other issues relating to my hormones all changing, so it is possibly related to that. It doesn’t bother me. I’m not afraid of it. I thought perhaps others might be experiencing it too and decided to look it up. Glad to see there are plenty of other people all in the same boat.

  4. nobody knows how or why this happens. At first, I thought it was a neighbor slamming a door or something. Anyway, my son witnessed this when I was falling off to sleep. I heard a huge bang. I woke up, said to my son did you hear that? He was like ‘no’ as he was casually playing on the ps4. It has happened many times. Also I have heard my front room door knock 3 times as clear as a bell. It’s strange and after finding this website I don’t feel like I’m losing my mind :)

  5. I’ve had sleep paralysis for many years and it happens so often that I’ve learned how to get out of it. By strong will, I can move and if I move enough I eventually get out of it (feels like moving through thick mud and I’ve had out of body experiences doing it too) if I go back to sleep I’ll have a night terror. But I have always heard whispers or my name called when falling asleep with the occasional boom flash. The boom always confused me and I’d go outside to look at the sky. Recently I’ve been hearing the boom every night. It wasn’t until one morning where it sounded like several men and women were screaming outside. It got louder and faded out as I woke up. Scared me frozen until I woke up fully and realized it came from my head and looked up online to see if I’m going crazy lol. The booms do cause me distress considering I already have anxiety going to sleep wondering if I’m going to wake up unable to move. Sleep paralysis you never get used to. I keep my eyes closed cause I see shadows around me that look like humanoid birdlike things. It’s been making it difficult to sleep much recently.

  6. First time for me last night. Just glad to find out what it was. I awoke from my dream clearly hearing a door slammed and a man screaming ‘bugger off’!! I jumped out of bed but was too scared to open the bedroom door. I then realized my husband was still fast asleep. My heart was racing and it took forever to convince myself no-one was downstairs. I am really hoping that it is a one-off. I’m 62.

  7. It is apparently benign. It helps that I have never experienced it to be frightening, and it occurs when I am dropping off to sleep. I “hear” a single sudden sound which is rather like a drumbeat. Sometimes I “see” a flash. I also experience hypnic jerks, and apparently, that has something to do with magnesium (which I do take, as I am also prone to painful leg cramps, and it has other benefits).

  8. Second night for me. Never had issues before. First time I was getting ready to go to bed when I heard what sounded like a gunshot. Tonight it woke me up. It is now 3 am and I am online trying to find out what is wrong with me. I toss and turn most nights. So to bed tired and wake up tired. Melatonin doesn’t always help me sleep. I am 73 and female. I have vertigo so I am assuming an inner ear issue.

  9. I started hearing loud bangs this last year. I have experienced it a couple of times. The sound I hear is like a gunshot or explosion. It never scares me, it’s more like what was that? I did have night terrors as a child. Not sure if there’s a connection. I’m a horrible sleeper. I constantly toss m turn never comfortable, wake up at least 4 times a night. I go to bed tired and wake up tired.

  10. I’ve just started having these episodes. I hear three loud raps on my bedroom door, like somebody hitting it with their knuckles trying to wake me up, but it doesn’t feel especially frightening or threatening. It just feels a bit strange. I’m in a very remote location with no passers-by.

    I had two episodes over three nights last week and I literally hear the knocks as I’m waking. I’m a poor sleeper anyway and I vape cannabis-based cartridges prior to settling down for the night. It seems EHS is more common with cannabis users. I’m also in the mid-50s age group where EHS seems more prevalent.

    Last night, I had my third episode although the knocks did seem much further away. I’m 95% certain it’s all in the head and even if it isn’t, it’s more startling than frightening anyway. A bit bizarrely, my daughter lives in the next nearest property and over the past four years, she’s heard knocks in the night from time to time too but nobody else has and she does share a room with her sister.

    I’ll keep watching this page with interest. Fascinating stuff!

    • Paul, Your daughter may be experiencing it because it can be an inherited genetic, neurological type disorder. It can be caused by mini-seizures. Worth an MD to rule out physiological issues first. I experience this and olfactory hallucinations, as in smelling roses, cig smoke, etc. I also have kinetic? where I feel a person so close they ran a finger down my arm while spooning. Touch was so lite just touch the little hairs etc. Migrainesm white flashes, colorful lights when eyes closed………..