====== Hypnic jerks ======

//Hypnic jerks// (a.k.a. //hypnagogic jerks, sleep starts, sleep twitches, myoclonic jerks, night starts// etc) are brief and sudden involuntary muscle contractions (twitches) which happen as a person (or other mammal) is beginning to fall asleep. They can be severe enough to wake the sleeper. Approximately 70% of people have experienced them.

They are benign, and occur randomly in healthy people.

Various factors are known to increase the likelihood of hypnic jerks - such as caffeine, nicotine, exercise, stress etc etc.  The cause is unknown, and none of the several theories that have attempted to explain them has been fully accepted.

See [[https://en.wikipedia.org/wiki/Hypnic_jerk#Causes|Wikipedia]]

//Note:// Hypnic jerks are not thought to be linked with [[content:medicine:diseases:r-z:restless_leg]]