# Occasional involuntary muscle spasms - something to worry about? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [March 11, 2012, 8:40pm UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486 "2012-03-11T20:40:29Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![Rigamarole](https://avatars.discourse-cdn.com/v4/letter/r/77aa72/32.png) [@Rigamarole](https://boards.straightdope.com/u/Rigamarole)\ **Post date:** [March 11, 2012, 8:40pm UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/1 "2012-03-11T20:40:29Z")
For a long time I’ve experienced this, and it’s always when I’m tired (usually it occurs when lying in bed about to go to sleep). I’ll feel somewhere in my body a muscle twitch involuntarily. It’s usually in the lower body (ankle, leg, thigh) but once in a while I’ve felt it in the upper body. This used to happen pretty rarely (like maybe once a week if that), but lately I’ve noticed it happening more often (pretty much every day). I have a doctor’s appointment in about a month during which I definitely plan to ask about it, but I’m just curious whether this could be a sign of something troublesome that I might need to deal with sooner, or if it’s normal. For the record, I have no other symptoms that I can tell and feel otherwise healthy. ---
**Author:** ![Al\_Bundy](https://avatars.discourse-cdn.com/v4/letter/a/e79b87/32.png) [@Al\_Bundy](https://boards.straightdope.com/u/Al_Bundy)\ **Post date:** [March 11, 2012, 11:02pm UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/2 "2012-03-11T23:02:07Z")
Never a bad idea to go to the doctor, unless of course you are me. Muscle spasms can have causes that are impossible to diagnose. It could be a mineral deficiency or an absorption difficulty. You may require something more than the norm so a standard diagnosis can miss something. The doctor will run appropriate tests and you will feel better that the sky is not falling. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [March 11, 2012, 11:30pm UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/3 "2012-03-11T23:30:34Z")
A pretty common symptom, and generally benign. Ask your doc, but I would not worry over it in the meantime. And yes, IAAMD ---
**Author:** ![ZipperJJ](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/zipperjj/32/211_2.png) [@ZipperJJ](https://boards.straightdope.com/u/ZipperJJ)\ **Post date:** [March 12, 2012, 12:29am UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/4 "2012-03-12T00:29:00Z")
It never hurts to hydrate! ---
**Author:** ![Askance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/askance/32/8281_2.png) [@Askance](https://boards.straightdope.com/u/Askance)\ **Post date:** [March 12, 2012, 1:05am UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/5 "2012-03-12T01:05:16Z")
This is called [Hypnic Jerk](http://en.wikipedia.org/wiki/Hypnic_jerk) and is very very common. Absent any other symptoms you have nothing to worry about. ---
**Author:** ![gerund](https://avatars.discourse-cdn.com/v4/letter/g/ed655f/32.png) [@gerund](https://boards.straightdope.com/u/gerund)\ **Post date:** [March 12, 2012, 1:33am UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/6 "2012-03-12T01:33:26Z")
If it’s while falling asleep, it’s a myoclonic jerk. The twitching of a muscle that occurs intermiitently throughout the day is called a benign fasciculation. ---
**Author:** ![Mama\_Zappa](https://avatars.discourse-cdn.com/v4/letter/m/71e660/32.png) [@Mama\_Zappa](https://boards.straightdope.com/u/Mama_Zappa)\ **Post date:** [March 12, 2012, 2:28am UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/7 "2012-03-12T02:28:31Z")
If I use the term “hypnic jerk”, I’m not calling you names ;). > **[Hypnic jerk](https://en.wikipedia.org/wiki/Hypnic_jerk)** > > A hypnic jerk, hypnagogic jerk, sleep start, sleep twitch, myoclonic jerk, or night start is a brief and sudden involuntary contraction of the muscles of the body which occurs when a person is beginning to fall asleep, often causing the person to jump and awaken suddenly for a moment. Hypnic jerks are one form of involuntary muscle twitches called myoclonus. > Physically, hypnic jerks resemble the "jump" experienced by a person when startled, sometimes accompanied by a falling sensation. Hypnic j... Causes include fatigue and stress, among others. ---
**Author:** ![Rachellelogram](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rachellelogram/32/8689_2.png) [@Rachellelogram](https://boards.straightdope.com/u/Rachellelogram)\ **Post date:** [March 12, 2012, 6:55am UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/8 "2012-03-12T06:55:19Z")
Yeah, it happens sometimes. It hasn’t happened to me in a while, thankfully. It can be really unnerving because it jerks you out of a nice sleepy drift, but not uncommon or dangerous. ---
**Author:** ![mhendo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mhendo/32/3159_2.png) [@mhendo](https://boards.straightdope.com/u/mhendo)\ **Post date:** [March 12, 2012, 7:01am UTC](https://boards.straightdope.com/t/occasional-involuntary-muscle-spasms-something-to-worry-about/615486/9 "2012-03-12T07:01:49Z")
I started a [thread](http://boards.straightdope.com/sdmb/showthread.php?t=529515) about this a couple of years ago. For me, this started soon after i started exercising regularly again after a considerable hiatus. It still happens to me occasionally, but not as much as it did for the first year after i started exercising. As i noted in that thread, the main dangers that we found resulting from this phenomenon were: 1. me clocking my wife in the head with a twitching arm while we were in bed, and 2. me striking my arm on the edge of our coffee table when i twitched during an afternoon nap on the couch.