Hypnic jerks, sometimes called sleep starts, are muscle contractions that occur involuntarily in a person when falling asleep. These sudden, jerking movements can be shocking, making you suddenly wide awake. They are a common experience, though the exact reason why hypnic jerks occur is unknown. In this blog, we’ll examine both the how’s and why’s behind these jerks, what might trigger them, and several ways to diminish their occurrence.
Hypnic jerks are rapid, involuntary muscle contractions. They usually happen during the transition from wakefulness to sleep, a stage known as hypnagogia. It’s believed that the jerks occur when the brain misinterprets the muscle relaxation that accompanies the sleep onset as a sign of falling, causing the muscles to contract as a reflexive response. This process, while generally harmless, can be jarring and lead to disrupted sleep.
These jerks usually affect one side of the body, like the arm or leg, and occur most often randomly as you’re drifting into sleep. In most cases, they are fleeting and not damaging long-term. But some people find them to be disruptive to their sleep.
Despite extensive research, the exact mechanism behind hypnic jerks remains unclear. It is believed that these jerks may stem from a miscommunication in the brain. As the brain shifts from wakefulness into sleep, it may mistakenly interpret the relaxation of the muscles as a fall, triggering a reflex to ‘catch’ oneself.
Hypnic jerks may also happen in response to the clear, dream-like images that typically come with this stage of sleep. Stress, anxiety, and sleep deprivation can worsen this phenomenon. What’s more, some habits can make the jerks occur more often or with more power.
Factors That Increase the Likelihood of Hypnic Jerks
Hypnic jerks happen for a variety of reasons, and knowing what makes them worse can help.
Excessive Stimulant Consumption
Substances like caffeine and nicotine are stimulants that can interfere with the brain’s ability to relax. These substances linger in the body for hours, potentially disrupting sleep and increasing the chances of hypnic jerks. Limiting caffeine intake, particularly in the afternoon or evening, can significantly improve sleep quality and reduce these jerks.
Vigorous Exercise Before Bed
Regular exercise is good for general health and sleep quality, but vigorous exercise in the hours before bed can result in a heightened state of alertness. Try to wrap up any vigorous physical activity at least two hours before you pack things in for the night, providing your body with at least that much time to cool down. If you pull a train through the day, it’s better to do yoga or light stretching for your body.
Sleep Deprivation
Lack of sleep, whether due to chronic insomnia or occasional poor sleep, can heighten the chances of hypnic jerks. Sleep deprivation disrupts the body’s natural rhythm and makes it harder to transition smoothly into the deeper stages of sleep. Ensuring you get adequate rest each night is one of the most effective ways to prevent jerks.
Emotional Stress and Anxiety
Both short-term stress and long-term anxiety can interfere with the quality of your sleep. When you are stressed, your body remains in a heightened state of alertness, making it difficult to relax enough to fall into deep sleep. The resulting sleep deprivation may then trigger hypnic jerks. Practising relaxation techniques, such as deep breathing or mindfulness, may help reduce the impact of these emotions on your sleep.
How to Reduce the Frequency of Hypnic Jerks
While it may not be possible to completely eliminate hypnic jerks, there are steps you can take to reduce their occurrence and improve your overall sleep quality. Here are a few strategies:
Manage Stress and Anxiety
Since stress is a major trigger for hypnic jerks, finding ways to relax before bed can help alleviate them. Consider incorporating calming activities into your evening routine, such as reading, listening to soothing music, or taking a warm bath. If anxiety is affecting your sleep on a regular basis, speaking with a therapist could also be beneficial.
Avoid Stimulants Before Bed
Limiting caffeine and nicotine consumption, especially in the afternoon and evening, can significantly improve sleep quality and reduce hypnic jerks. These stimulants can keep the brain alert when it should be winding down, making it more likely to misfire during the sleep transition.
Exercise Regularly
Regular exercise helps promote restful sleep, but be mindful of when you work out. Vigorous physical activity close to bedtime can make it harder to fall asleep, so try to finish any intense workouts at least a few hours before going to bed. If you’re only able to exercise in the evening, low-impact activities like yoga or walking can be less disruptive.
