The reason your body suddenly twitches as you fall asleep

That falling sensation while drifting off to sleep that most of us have experienced is known as hypnic jerks or sleep starts.

The term hypnic, which is the short form of the word hypnagogic, represents the transition between wakefulness to sleep. This is the phase when these twitches occur. Researchers don’t know the exact reason why these jolts happen, but they do provide various theories.