The science and symptoms of sleep paralysis In REM sleep, our bodies are paralyzed so we don’t act out our dreams and risk hurting ourselves or others, Jalal said.

The science and symptoms of sleep paralysis. In REM sleep, our bodies are paralyzed so we don't act out our dreams and risk hurting ourselves or others, Jalal said.

Around 30% of people will experience sleep paralysis at least once. Here’s why and what you can do about it.