They're called hypnagogic jerks. Here's why they might be happening.
While the brain controls when and how we move, there are times when it seems like the body has a mind of its own. Every once in a while, you may experience a twitch or muscle contraction that is completely out of your control. Is this a worrisome sign of a glitch in the system?
One common time the body jerks at a random time is right before you’re about to drift off to sleep. Out of nowhere, you may feel your arm or leg start to twitch. “If you’ve ever been drifting off to sleep and are suddenly awakened by a strong and involuntary bodily twitch, you have experienced the phenomenon of hypnagogic jerks,” says Dr. Michael Green, MD, the chief medical officer at Winona, a wellness platform for women.
Hypnagogic jerks are a type of myoclonus, which Dr. Green says is the clinical term used to describe sudden, involuntary muscle movement that causes sudden body jerks. “Myoclonus is typically brought on by a disturbance in the central nervous system,” he says. Dr. Green says this can happen when there is an injury to the head or spinal cord, or if someone has experienced a stroke. But there are other, more common reasons they can happen too.
6 Reasons For Random Body Jerks, According to Doctors
1. You’re sleep-deprived
Dr. Emmanuel Mignot, MD, PhD, who is the Craig Reynolds Professor of Sleep Medicine in the Department of Psychiatry and Behavioral Sciences at Stanford University and the Director of the Stanford Center for Narcolepsy, says that there isn’t a lot of data on hypnagogic jerks, but what is known is that they correlate with sleep deprivation. One theory is that, as muscles relax, the brain misinterprets this as the body falling, so it sends a signal to muscles to twitch as a way to protect the body.
2. You had a day of intense physical activity
If you sit down after a long day where you ran a race, spent the day helping a friend move, or did another activity that put your body to the test, Dr. Green says that you may experience some involuntary body jerks. “Contraction of the muscles can be a side effect of physical activity, so it’s not surprising that hypnagogic jerks can present after exercise,” he says. This can happen because your muscles are so used to being fired up that it can take them some time to realize that they can now rest.
3. You’re over-caffeinated
According to Dr. Green, people who consume excessive amounts of caffeine are more likely to experience hypnagogic jerks. Caffeine can interrupt the sleep-wake cycle and body jerks can be one side effect of this.
4. You’re heading to bed after drinking
Alcohol is yet another drink that can cause body jerks when consumed excessively, according to Dr. Green. It’s for a similar reason as caffeine; alcohol can interfere with the body’s sleep-wake cycle.
5. You’re stressed out
Seriously, what doesn’t stress affect? If you’ve ever climbed into bed while feeling anxious, you know that stress can be a roadblock to getting a good night’s sleep. But how can it affect your muscles and cause twitching? Experts at The Sleep Foundation explain that stress raises cortisol levels (a hormone that’s literally known as “the stress hormone”), which can make sleep less restful. It’s basically as if the body’s at war with itself; you’re tired yet can’t sleep. This conflict can result in body jerks as the body lingers between being awake and falling asleep.
6. You may have a metabolic disorder
In rare cases, Dr. Green says that experiencing body jerks could be a sign of a metabolic disorder and a sign that the central nervous system is being impacted. Again, it’s not likely, but it’s still something to be aware of.
What To Do If You Experience Random Body Jerks On a Regular Basis
Experiencing a body jerk every now and then isn’t cause for concern, but if you find that it’s happening to you frequently, there are diet and lifestyle changes that may help prevent it from continuing to happen. Dr. Green says to first examine your dietary habits. Are you consuming a lot of caffeine or alcohol on a regular basis, which could be impacting your sleep cycle, and in turn cause your muscles to twitch? If so, cut back.
Dr. Green says that another possible lifestyle habit that can help is avoiding exercising in the evening. That way, your muscles won’t be confused about whether it’s time to work or rest when you head to bed.
“Taking a magnesium supplement could be helpful because magnesium is a natural muscle relaxer,” Dr. Green says. There are many foods that have this nutrient too, including pumpkin seeds, cashews, oatmeal and spinach.
Last but certainly not least, see your healthcare provider. “You should never hesitate to speak to your physician if you feel concerned about anything your body is doing—especially if the jerks are causing you to suffer from insomnia,” Dr. Green says. This way, your doctor will also be able to see if any underlying conditions could be causing you to experience body jerks.
It bears repeating that, generally, hypnagogic jerks aren’t a cause for concern. Like hiccuping or sneezing, sometimes, the body acts in a way that we don’t have control over. But if it keeps happening to you, fill in your doctor. Unlike body jerks, booking an appointment is something you can control.