Have you ever been asleep when you suddenly hear what sounds like a gunshot, a door slam, or an explosion inside your head? You wake up, your heart is pounding, you sit up in bed, but the room is silent.
Nothing has happened – but it was very real.
This experience has a dramatic name: exploding head syndrome.
Despite the alarming name, it is not dangerous, it is not painful and it is not a sign that something is wrong with the brain.
What is it?
Exploding head syndrome is a type of sleep disorder known as parasomnia.
Parasomnias are unusual experiences that occur during sleep or during the transition between sleep and wakefulness.
In exploding head syndrome, a person “hears” a sudden noise that seems to come from deep inside the head. It is a sensory perception created by the brain and not an external sound.
It usually occurs when drifting off or coming out of sleep, more often when a person is drowsy and ready to fall asleep.
People usually describe a sudden pop or loud metallic noise, gunshots, an explosion, crashing waves, humming electricity, a slamming door, or fireworks.
Exploding head syndrome can be intensely frightening. The loud noise may be accompanied by another sensationsincluding a brief stabbing pain in the head (although usually painless), flashes of light, out-of-body sensations, or the sensation of electricity coursing through the body.
The episode lasts only a split second or a few seconds and usually disappears completely once the person wakes up. Some people experience only one episode, while others may have occasional episodes or short clusters before the condition resolves.
Because the experience is so sudden and unusual, many are afraid they had a stroke or seizure or that something catastrophic happened. Others interpret it as a supernatural or ominous event.
Anxiety is not caused by pain, but by the body’s confusion and alarm response. The brain is partially awake, disoriented, and briefly activates the fight or flight system.
What causes it?
We don’t know the exact cause, but researchers have proposed several theories.
Because the episodes occur during the transition to sleep and out of sleep, they may be related to the same processes that cause what are known as hypnagogic hallucinations (vivid sensory experiences you can have when you fall asleep).
As we fall asleep, different parts of the brain gradually turn off in a coordinated sequence.
In exploding head syndrome, this process may be associated with its closure neural systems that inhibit auditory sensory processing. Your brain may end up interpreting it as a loud sound.
A related one theory suggests a brief decrease in brainstem activity, particularly the reticular activating system (which is involved in regulating transitions between wakefulness and sleep).
Exploding head syndrome usually does not involve pain and is therefore different from headaches and migraines.
The distinctive features of the syndrome also make epilepsy an unlikely explanation for most people.
How common is it?
Exploding head syndrome is more common than you think.
It appears at least in 10% of the population and around 30% of people will experience it at least once in their lifetime.
It can appear at any age, often after the age of years 50. It may be slightly more common in womenbut we don’t know why.
Exploding head syndrome is more likely in people who have other sleep disorderssuch as insomnia or sleep paralysis.
Also associated with:
How is it treated?
Exploding head syndrome is harmless and not a sign of a serious brain problem. Episodes are usually brief and may occur sporadically or in short clusters before resolving on their own.
Once people are reassured that the condition is not harmful and is not a sign of brain damage or serious illness, episodes may become less frightening and frequent.
Medications are considered if episodes are frequent and very painful, but there have been no large clinical trials that can guide treatment. Some Sufferers have benefited from drugs such as clomipramine, but evidence is limited and more research is needed.
Most commonly, treatment consists of reassurance and improving sleep habits. Some people report that treating sleep problems such as insomnia, reducing fatigue and practicing mindfulness and breathing techniques can help.
Generally harmless
In 1619 the French philosopher René Descartes described having three dreams that he saw as signs of divine revelation. In one, he heard a loud noise and saw a bright flash when he woke up. Some researchers have suggested what it was really experiences it was exploding head syndrome.
Despite its dramatic name, exploding head syndrome is harmless. For many people, the most effective intervention is to understand what it is – and know that it is not dangerous.
Although they are generally harmless, you should seek medical advice if episodes occur frequently, affect your quality of life or cause discomfort. Consult a doctor if they are painful or associated with seizures, prolonged confusion, loss of consciousness, or severe headache.
