Exploding Head Syndrome (EHS) is classified as a parasomnia, a group of sleep disorders characterized by unusual and unpleasant experiences that disrupt sleep. This group also includes phenomena like sleep paralysis, where a person cannot move or speak while falling asleep or waking up, and so-called "sleep starts"—sudden involuntary muscle jerks as one drifts off to sleep.
Although the name of this syndrome sounds alarming, experts emphasize that EHS is not dangerous and is not considered a sign of brain damage. Professor Flavie Waters from the School of Psychological Science at the University of Western Australia explains that in this condition, a person "hears" a sudden sound in their head. It is a sensory experience that originates in the brain, not an actual external sound, and it occurs while falling asleep or waking up, most often in moments of drowsiness.
People describe EHS episodes as sounds of sudden noise, explosions, electrical buzzing, door slamming, or fireworks. The attacks usually last only a few seconds and leave no visible symptoms after fully waking up. Some have only one such experience in their lifetime, while others go through occasional episodes or short series of attacks before the condition spontaneously subsides. Many become frightened, thinking they have suffered a stroke or epileptic seizure, or that something catastrophic has happened, while others interpret this experience as a paranormal or ominous phenomenon.
The fear and discomfort accompanying EHS are not due to pain, but rather confusion and a strong reaction of the body's alarm system. The brain is partially awake, disoriented, and briefly activates the "fight or flight" response. For those who suspect they have experienced such a disorder, experts highlight several recognizable signs.
The first and primary sign is a sudden, loud sound that abruptly wakes the person, even though there is no real source of noise in the environment. Psychology lecturer at the University of York, Dr. Dan Denis, notes that episodes usually involve a brief but very loud sound during the transition from wakefulness to sleep. The sounds last only a few seconds, are extremely intense, and always without an apparent external cause.
Most people do not feel physical pain during an attack, according to data from the Cleveland Clinic. However, some patients report brief headaches. Physical pain occurs in a smaller number of individuals.
Exploding Head Syndrome is not limited to auditory experiences. Some patients also report brief visual hallucinations, such as flashes of bright light.
Additionally, some people experience intense bodily sensations during an episode. Descriptions include waves of intense heat passing through the upper body. Waters adds that some describe "electricity passing through the body" or even "out-of-body experiences."
Due to sudden awakening and shock, pronounced physiological reactions are not uncommon. Some people feel an increased heart rate. The Cleveland Clinic notes that patients often report sweating and difficulty breathing after sudden awakening.
Sudden jerks and muscle spasms are also common during EHS episodes. Medical literature indicates that EHS has been known to doctors since the 19th century. Denis points out that the syndrome was first documented in 1876, while Waters recalls records suggesting that French philosopher René Descartes may have experienced a similar phenomenon as early as 1619. Nevertheless, modern medicine clearly describes it as a harmless condition.
"Despite the dramatic name, Exploding Head Syndrome is harmless," emphasizes Professor Waters. The exact cause is not fully understood, but one theory links it to processes underlying sensory hallucinations during sleep onset. As she explains, as we drift off to sleep, different parts of the brain gradually shut down in a precisely coordinated sequence. In EHS, this process may be associated with the deactivation of neurons that normally inhibit auditory information processing, causing the brain to interpret this disruption as a sudden, powerful sound.
The phenomenon of EHS can affect anyone but appears somewhat more frequently in women. Individuals who already suffer from other sleep disorders, such as insomnia or sleep paralysis, more commonly report these episodes. It is estimated that EHS occurs in at least 10 percent of the population, and about 30 percent of people will experience it at least once in their lifetime.
As a form of self-help, it is recommended to address sleep problems like insomnia, reduce fatigue, and practice relaxation, mindfulness, and breathing exercises. Waters notes that one should certainly consult a doctor if episodes occur frequently, significantly impair quality of life, or cause severe emotional distress, reports <a href="https://www.klix.ba/redirect/260402014?url=https%3A%2F%2Fwww.thesun.co.uk%2Fhealth%2F30291140%2Fsigns-of-exploding-head-syndrome-sleep-disorder%2F" target="_blank">The Sun</a>.