Sleep paralysis is a condition in which we are conscious but temporarily unable to move or speak.It can usually occur when we suddenly wake up during REM sleep.

Basically, there are four stages of sleep.One of them is Rapid eye movement sleep, i.e., REM sleep.In this stage, we dream.Researchers suggest that when we enter REM sleep.Two chemicals, glycine and GABA ''switch off'' the activity of cells in the brain that allow our muscles to move.It is actually beneficial because paralyzed muscles prevent us from enacting our dreams in reality and getting hurt.However, sometimes we suddenly wake up during REM sleep.But if glycine are still active.We are temporarily unable to move, even though we are conscious.This is called sleep paralysis.