Nearly 80% of people who've injured themselves while sleepwalking felt no pain and didn't even wake up, according to a new study published this month in Sleep. And we're not talking about a stubbed toe or bumped elbow, either. One study subject jumped out a third-floor window—suffering multiple severe fractures—and didn't feel any pain until waking up later, according to an American Academy of Sleep Medicine press release. It was the same for another person who fell off his roof and broke his leg while sleepwalking. Of the 100 sleepwalkers studied by a French research team, 47 reported injuring themselves while sleepwalking at least once. But only 10 actually woke up immediately from the pain.
The study's lead researcher, Dr. Regis Lopez, says those numbers are surprising, according to the AASM press release. “Our results may help to understand the mechanisms of the sleepwalking episodes,” Lopez says. “We hypothesize that a dissociate state of arousal may modify the components of sleep-wake behavior, consciousness, and also pain perception.” As the International Business Times simplifies: Researchers believe there's some sort of connection between sleepwalking and the neurons that send pain signals to the spinal cord and brain. The study also found sleepwalkers are nearly four times more likely to report a history of headaches and 10 times more likely to report suffering from migraines while awake. (See what the chance you've sleepwalked before is.)