There’s a long list of weird things that can happen when you sleep—think sleepwalking, sleep sex, or even waking up unable to move your body. But as for the noises you make, those are pretty normal, right?
Well, not all the sounds you make when you sleep are regular old snoring. In fact, there’s a condition called catathrenia, or sleep groaning, which is more common than you may think.
While research suggests sleep groaning is rare— affecting 0.3 percent to 0.5 percent of the population—it’s likely the number is higher, since the condition often goes under-reported, says Rajkumar Dasgupta, M.D., an assistant professor of clinical medicine at the Keck School of Medicine at the University of Southern California.
“Many times, it’s a bed partner reporting it, not the person themselves,” he says. In fact, unless someone else hears you groaning, you’re likely not going to notice the problem yourself because sleep groaning often comes without daytime symptoms.
WHAT IS SLEEP GROANING?
Sleep groaning is classified as a parasomnia, which is a fancy term for unwanted behaviors, actions, or thoughts that occur while we’re falling asleep, sleeping, or waking up. Sleepwalking and sleep talking are other parasomnias.
Sleep groaning may sound like a snore, but its cause is different. A snore happens when you inhale. You take a breath in, and the relaxed muscles and tissues in your windpipe vibrate, causing that buzzing noise.
A sleep groan, on the other hand, happens when you exhale. And one groan can last anywhere from 30 seconds to a minute, says Dr. Dasgupta.
Dr. Dasgupta says a sleep groan typically sounds like, well, a groan. It might even have a Chewbacca-type moaning noise to it, he notes.
The American Sleep Association explains that groans might also be followed by a snort or a sigh at the end.