HAVE you ever been jerked awake by a loud bang in your head as you’re drifting off to sleep?
You might have experienced a poorly understood sleep disorder that actually affects one in three people, dramatically dubbed ‘exploding heads syndrome’.
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Referred to as EHS, the syndrome belongs to a family of sleep disorders known as parasomnias, which involve unusual and unpleasant events that disrupt our snooze.
They include sleep paralysis – the feeling of not being able to move or speak as you’re waking up or falling asleep – and hypnic jerks.
Also known as ‘sleep starts’, these are sudden, involuntary muscle contractions that strike as you’re drifting off.
According to Dr Dan Denis, a lecturer in psychology at the University of York, medical professionals have known about EHS since “at least 1876”.
Despite this, little is known about it and few studies have sought to look into its causes.
How many people are violently shaken awake by imaginary sounds of explosions is not entirely clear, Dr Denis wrote in The Conversation.
A study published in 2017 found that 11 per cent of otherwise healthy adults experienced EHS, while another of undergraduate students published two years prior found 17 per cent of participants had experienced multiple episodes in their lifetime.
“In my own, more recent study, again in undergraduate students, my colleagues and I found that one-third of our sample had experienced at least one episode of EHS in their lifetime, with around 6 per cent experiencing at least one episode a month,” Dr Denis said.
His study also suggests that people experiencing EHS episodes might also experience other parasomnias like sleep paralysis – “with the suggestion that exploding head syndrome may temporally precede an episode of sleep paralysis”.
“It is also possible that poor sleep quality in general, perhaps exacerbated by factors such as stress and anxiety, is a risk factor for unusual sleep experiences,” Dr Denis adds in his 2018 study.
Wondering if your own sleep has been disturbed by this peculiar syndrome.
Here are six signs of it to know.
1. A loud noise
As mentioned, a telltale sign of EHS is being jolted awake by a loud sound in your head.
According to Dr Denis, episodes typically involved hearing an abrupt loud noise “during the transition from wakefulness to sleep”.
“The sounds that are heard during EHS are variable, and include perceptions of gun shots, doors slamming, or nondescript screaming,” he explained.
“Importantly, the sounds that are heard are always short (a few seconds or less), very loud and without any obvious external source in the environment.”
2. Feeling like your head is ‘exploding’
The clue for another key sign that you might be experiencing EHS comes in the name – “a sense of an explosion inside the head”, according to Dr Denis.
You don’t actually experience physical pain during an EHS episode, according to Cleveland Clinic.
As Dr Denis explained in his study: “Whilst not typically associated with physical pain, episodes can result in clinically significant levels of distress or impairment in some cases.”
He noted that physical pain is only reported by 9 per cent of those experiencing EHS, while 7 per cent say they’re left with headaches.
3. Hallucinations
Hearing unusual sounds isn’t the only sign of EHS.
According to Dr Denis, “some people experience accompanying brief visual hallucinations such as bright flashes”.
“Approximately one-third of the sample reported visual phenomena such as flashing lights,” he wrote in his research.
4. Intense heat
Some EHS sufferers are also struck by physical sensations during an episode.
“Others have also reported feelings of intense heat, or the sensation of electrical charge flowing through the upper body.”
5. Increased heart rate
If you’re startled awake by a loud sound, it’s natural that your body will respond accordingly.
Eighty-three per cent of participants in a 2018 study establishing clinical symptoms of the condition said they were left with an increased heart rate after an episode.
According to Cleveland Clinic, sufferers can often also wake up sweating and with difficulty breathing.
6. Muscle jerks and twitches
According to Cleveland Clinic, experiencing a sudden muscle jerk during an EHS episode is also common.
A study published in the 2018 study found that 68 per cent had muscle jerks and twitches.
“Despite its provocative name, EHS is harmless,” Dr Denis said.
“Encouragingly, simply learning that EHS is a common and harmless condition can go a long way,” he went on.
Other sleep disorders
Sleep disorders are conditions that affect your ability to get the rest your body needs.
There are many different types of sleep disorders, but some of the most common include:
- Chronic insomnia – you have trouble falling asleep or staying asleep most nights for at least three months and feel tired or irritable as a result
- Obstructive sleep apnoea – ou snore and have moments during sleep when you stop breathing that disrupt your sleep
- Restless legs syndrome – you have the irresistible urge to move your legs when you rest
- Narcolepsy – you can’t regulate when you fall asleep or how long you stay awake.
- Shift work sleep disorder – you have trouble falling asleep and staying asleep and feel sleepiness at unwanted times due to your work schedule
- Delayed sleep phase syndrome – you fall asleep at least two hours after your desired bedtime and have difficulty waking up in time for school or work
- REM sleep behavior disorder – you act out your dreams while in the rapid eye movement (REM) stage of sleep
Source: Cleveland Clinic
“In a patient case study, it was reported that reassurance and education about the experience stopped the episodes from happening.
“This is not to say that EHS cannot be a scary experience,” the expert noted.
