Sleepwalking. If you’ve ever experienced this strange phenomenon—or lived with someone who has—then you know how frightening it can be. Around 8.4 million (a little over 3% of the population) American adults are prone to sleepwalking, making it an uncommon, but not quite rare, sleep disorder.

Because we know nothing about sleepwalking, we asked clinical sleep psychologist Katherine Hall to walk us through sleepwalking. Read on for everything you need to know!

COOP: How much do we know about sleepwalking? When does sleepwalking occur?

KATHERINE HALL: Whilst research into sleepwalking is ongoing, what we do know is that it usually occurs during deep sleep, which peaks in the early part of the night. As a result, sleepwalking typically occurs in the first few hours after falling asleep.

C: What causes sleepwalking?

KH: Although the exact cause of sleepwalking is still unknown, what we do know is that sleepwalking appears to occur when a person gets partially awoken while in deep sleep.

There are a number of factors that can influence or trigger this partial awakening:

• Sleep deprivation
• Stress and anxiety
• Infection with a fever, especially in children
• Drinking too much alcohol
• Genetic predisposition to sleepwalking

C: Is sleepwalking dangerous?

KH: Some episodes of sleepwalking may involve sitting up in bed or slowly walking around, getting dressed or moving items in the home. However, there have been cases whereby, in extreme cases, the person can walk out of the house or carry out more complex, worrying activities, such as attempting to drive a car.

The first thing to do if you find someone sleepwalking is to ensure that they are safe. You should try and gently guide them back to bed with care and reassurance. They will usually simply go back to sleep once they reach their bed again.

You should avoid shouting or startling the person as this sudden jolting awakening may provoke fear which could put you in harm’s way.

C: Does sleepwalking occur more in some demographics than others?

KH: Sleepwalking occurs more commonly in children with studies suggesting that one in five children will sleepwalk at least once. Many children grow out of sleepwalking by the time they reach puberty, however, in a small number of cases, can persist in adulthood.

C: Is sleepwalking genetic?

KH: It appears to be, yes. If one parent has a history of sleepwalking, children are three times more likely to sleepwalk themselves. And if both parents had a history of sleepwalking, that number significantly rises.

C: Can we prevent sleepwalking at all?

KH: Whilst there is no specific treatment for sleepwalking, having good sleep hygiene usually helps. Sleep hygiene refers to positive habits we use to help us sleep. Good sleep hygiene includes behaviors and factors such as having a consistent bedtime and wake time or stopping any stimulating activities such as watching TV or playing on your phone at least 60 minutes before bed.

Katherine Hall is a Sleep Psychologist with 13 years of clinical experience. She primarily specializes in Acceptance and Commitment Therapy (ACT) and Cognitive Behavioral Therapy for Insomnia (CBT-I). You can find her at Somnus Therapy, an online sleep therapy program to help those suffering from sleep problems.