What causes a a single, violent, whole-body "twitch" while falling asleep?
August 17, 2006 3:17 AM Subscribe
What causes a single, violent, whole-body "twitch" while falling asleep? This happens to me frequently, but irregularly. After going to bed, closing my eyes, and relaxing for some time, out of nowhere I'll experience a very strong, but very brief, muscular "jerk" involving what feels like the entire body.
posted by CodeBaloo to Health & Fitness (26 answers total) 5 users marked this as a favorite
Normally, this will jolt me back to being fully awake, and often wakes my wife as well. When it does wake me up, a have the sense (I feel that I know) it happened just at that very moment I "officially" fell asleep—almost as if my mind "popped the clutch" while shifting from awake-but-relaxed to asleep. The sensation is nearly identical to when someone sneaks up behind you and startles the Hell out of you as a joke. As far as I can tell, there is no common circumstance preceding this "twitch". Is there a name for this phenomenon? Is it common? And, most interestingly, what's happening neurologically or physiologically to cause it?