“Most patients say the same thing to describe sleep paralysis: that it feels like you woke up dead. You know that your mind is awake and your body is not — so you’re trapped, essentially,” Michael Breus, Ph.D., clinical psychologist and fellow of the American Academy of Sleep Medicine.
2. And it’s way more complicated than a nightmare..
“It is the complete opposite, actually,” Breus explains. When you enter deep REM sleep, your brain tells the body’s voluntary muscles to relax and go into almost a state of paralysis, which is called atonia. Atonia actually helps protect the body from injury by preventing you from acting out the physical movements in your dreams. In other parasomnias, such as sleepwalking or REM sleep behavior disorder, atonia does not occur properly and the voluntary muscles move while the mind remains asleep, which is why people can sometimes do crazy things in their sleep and be totally unaware of it.