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Jolted Awake by Hypnic Jerks?
Just as I'm about to fall asleep, I jerk awake. This has been happening frequently for about a year and is preventing me from getting a good night's sleep. What causes this? My doctor says the problem will disappear on its own but has prescribed medication to help me sleep. Do you have any other advice?
Answer (Published 4/2/2010)
You're describing involuntary muscle twitches known as hypnic jerks, sleep starts, or myoclonic jerks. They're very common; most people experience them from time to time, but we really don't know what causes them. One theory holds that they're a part of the general slowdown of the nervous system that occurs as you're falling asleep. Your breathing slows, your temperature drops and muscle tone changes. Hypnic jerks, this theory goes, occur as a result of the muscle transition. Another theory holds that just as you're drifting off to sleep, your brain misperceives all that relaxation as a sign that you're falling, and alerts your arms and legs to stay upright. While the physiology of these involuntary movements remains unknown, we do know that you're more likely to experience hypnic jerks if you have poor sleeping patterns or have been sleep deprived.
Because hypnic jerks are considered medically harmless, there's not a lot of research on them. I found only eight studies in a medical literature search - the most recent was published in 2007 and was just a review of the differences between various sleep-related movement disorders. Most of the others were related to children.
I suggest that you consult a sleep expert. The solution may simply be better sleep hygiene - steps you can take to eliminate obstacles to sound sleep. Here are my general recommendations for getting a good night's sleep:
Andrew Weil, M.D.
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