There is, of course, a good chance that you, dear reader, have never heard of EHS before. I confess that it is only within the last couple of years that I myself became familiar with the term via my friendship with the world’s leading expert on the topic, Dr Brian Sharpless. EHS is characterised by the subjective experience of abrupt, loud sounds just as one is drifting off to sleep or emerging from sleep. The noise doesn’t last long but can be jarring to the sufferer. In itself, the condition is quite benign, but it can cause considerable distress. Most sufferers only have occasional episodes, but it can have clinical consequences when occurring on a more chronic basis.

The sounds heard during episodes of EHS may be explosions (hence the name exploding head syndrome) but they may also be other sounds including roars, beeps, doors slamming, waves crashing, shouting, or the clash of symbols, to name but a few. Furthermore, additional symptoms are commonly reported to occur such as tachycardia (fast heart rate), fear, and muscle jerks, along with less common symptoms such as sweating, seeing a flash of light, breathing difficulties, and a range of other anomalous bodily sensations.

Exact estimates of lifetime prevalence rates are not available but what data there are suggest the condition is not rare, probably affecting around one person in ten in the general population.