Book Definition: A condition in which a person sleeping is unable to move any of the voluntary muscles, except the muscles controlling the eyes. Sleep paralysis normally occurs during the REM sleep stage.

In Your Own Words

  • Sleep Paralysis occurs during REM sleep. Sleep paralysis occurs so a person can not act out a dream and hurt themselves and/or other people.
  • When the REM sleep stage occurs, the body is paralyzed and the only moving muscles are the muscles in the eyes.
  • From an evolutionary perspective, sleep paralysis helped keep our ancestors from walking off of a cliff or performing any other hazardous acts while acting out their dreams.
  • The stage of sleep where your body gets rest and your brain is active.
  • The non-movement of your voluntary muscles and body parts when in a REM sleep.
  • When you can't move your body during REM sleep.


  • Like many young children, some may dream about waking up to use the bathroom and envision themselves getting out of bed to do so, yet they cannot move voluntary muscles to get up during their dream, which results in bed-wetting.
  • If you're dreaming about a komodo dragon and swatting it with your hand and running away, sleep paralysis prevents you from jumping out of bed and running, but you can still kick and swat in your dream.
  • When a dog runs in his sleep and smacks into a wall, he is lacking sleep paralysis.
  • Sleep paralysis is the main reason that the human population exist today, it prevents people from moving in their sleep which halts dangerous sleeping movements such as walking off a cliff.

Sample Questions

True or False?
1. Sleeping Paralysis occurs during Stage 4 of sleep. (False)
2. Sometimes when you fall in your dream, it can wake you up and make you fall in your bed. (False)
3. If your running in your dream, because of Sleeping Paralysis, you wouldn't be running in your bed. (True)

Additional Resources