Exploding Head Syndrome (EHS) is an actual medical condition in which an individual sometimes experiences an explosive sound inside their head when drifting off to sleep or just waking up. The big boom may also be accompanied by a flash of light. Also called "episodic cranial sensory shock," cases have been reported in the medical literature since the 19th century although the phenomenon is not well studied. In 2017, the BBC's Science Focus magazine and academic collaborators launched a survey about EHS and the results have just been published in the scientific journal Sleep Medicine:
Those with EHS had shorter sleep durations, longer sleep onset latencies, poorer sleep quality, and less sleep efficiency, but effect sizes for these differences were small. Females were slightly more likely than males to endorse EHS. 44.4% of individuals with EHS experienced significant fear during episodes, but fewer reported clinically significant distress (25.0%) or interference (10.1%) as a result of EHS. Most sufferers believed it to be a brain-based phenomenon, but a small minority endorsed anomalous causes. Five prevention strategies with >50% reported effectiveness were identified.
From Science Focus:
"Exploding Head Syndrome (EHS) is not discussed very much in the media or elsewhere. Consequently, people having this experience may have very little information about what is going on," said [Goldsmiths psychology professor Alice] Gregory.
"In our study, we found that those who had experienced EHS reported poorer sleep quality and less sleep than others. In future, we would like to understand more about these associations. For example, could disturbed sleep trigger this experience, or is it that someone who has experienced EHS finds it more difficult to fall asleep at night?"
