If you know someone who sleepwalks, or sleepwalk yourself, you've probably come across the idea at some point that you should never wake a sleepwalker.
The idea is an old one. Incredibly old, in fact, with sleep specialist at Stanford University Dr. Mark Mahowald telling LiveScience that it comes from an ancient belief that your soul leaves your body while you sleep, and so waking a sleepwalker would cause the sleeper to walk the lands soulless from then on. Which – stop us if we're getting too controversial – doesn't sound like the most scientific basis for deciding whether or not to wake up a loved one when they're wandering the house at night.
We now know a lot more about sleep and sleepwalking, and the risks of waking someone up vs letting them continue their night walk. Rumors that waking a sleepwalker could cause them to slip into a coma, or have a heart attack, are not correct. However, that doesn't mean you should definitely wake them up, either.
"When someone is sleepwalking, they're stuck between deep sleep and light sleep and if you try to wake them up, they will be very confused and disorientated," Professor Harriet Hiscock of the Murdoch Children's Research Institute told ABC.
"You're not going to give them a heart attack or kill them, but by trying to wake them up – which is usually quite hard to do – you can make them very agitated."
Sleepwalking – though disorientating, and at times distressing – is not in itself harmful to your health, according to UAMS Pulmonologist and Sleep Medicine Specialist Dr Raghu Reddy, who adds that there are still other risks.
"It can cause problems indirectly mainly due to safety concerns – walking out of the house, jumping out of the window, using lighters and kitchen knives, bumping into sharp objects, etc.”
On the more extreme end, sleepwalkers have been known over the years to drive whilst sleepwalking, or – like one 15-year-old girl in 2005 – climb up a 40 meter (130 foot) crane, before falling asleep again on the arm, before thankfully being rescued. Though waking sleepwalkers in such extreme circumstances (or if you think they might injure themselves without finding a giant crane) is probably justified, you should still do so carefully.
“There is no consensus on what is the best approach when one encounters a sleepwalking patient. It is not dangerous to wake up a patient from sleepwalking, but experts who discourage it quote it is unsuccessful and leads to patient disorientation,” Reddy added.
“Try to ease them back to bed without making forceful attempts. If unsuccessful, just watch closely to assure their safety and try again after some time has passed.”
Sleepwalking generally happens during childhood, and is something that resolves by itself. However, should you sleepwalk regularly, or you're concerned you may cause injury to yourself or others it is worth contacting your physician.