What causes your body to jump when sleeping?

Answer:
It's not known exactly what causes the twitches, but they appear to be associated (although by no means invariably) with (a) anxiety and (b) some faint stimulus, such as a noise. Most scientists who study sleep patterns attribute it as a sort of sudden "unwinding" of the bodily "spring". It is considered normal, and nothing to worry about.
First answer by Melaina Truelove. Last edit by Melos Antropon. Contributor trust: 189 [recommend contributor recommended]. Question popularity: 2 [recommend question].