OK, it doesn't involve one's head literally exploding, but "exploding head syndrome" is no joke, say experts. "It's a provocative and understudied phenomenon," says psychologist Brian Sharpless of Washington State University after a review of studies. Sufferers experience explosive-sounding noises during transitions between waking and sleep. They may feel like they're hearing gunshots or fireworks. "I've worked with some individuals who have it seven times a night," Sharpless says. Others may only have it once, ever, the Daily Mail notes.
The result can be a fear of going to sleep as well as mild pain during the episodes—though the perceived noises themselves aren't harmful. Why does it happen? Experts aren't sure. "Our best guess is that it occurs when the body doesn't shut down for sleep in the correct sequence," Sharpless says. "Instead of shutting down, certain groups of neurons actually get activated and have us perceive the bursts of noise." It appears to be most common in women older than 50, eMaxHealth reports, but it's by no means limited to that group; in fact, it may occur in 10% of people, the Mail notes. According to eMax, the "best treatment" is simply learning that the disorder won't hurt you. (Another thing that actually exists, according to science: "short man syndrome.")