Why Do We Twitch and Jerk In Our Sleep & What Does It Mean?
6 min read
Last Modified 30 April 2021 First Added 25 January 2021
Twitching in your sleep. We’ve all been there. You’re about to drift off into the land of nod, when suddenly your body twitches or jumps and your limbs, for some reason, jerk in random directions. It may cause confusion or even amusement, but have you ever wondered what causes this bizarre phenomenon? We look into scientific theories to find out what causes jerking and twitching in sleep.
Twitching in sleep is academically known as a ‘hypnagogic jerk’ or a ‘hypnic jerk’. It got its name because these twitches usually occur while you are in the hypnagogic state, which is in between being awake and asleep. According to the BBC, they are most common in children and are basically an unconscious muscle spasm that occurs as you are drifting off to sleep. Hypnic jerks can be completely random or induced by certain triggers, such as sound or light.
Sleep expert Dr. Natalie Dautovich states:
‘As we transition from wakefulness to sleep, we experience a hypnagogic state of consciousness. During this state, we can experience unique phenomena including a hypnic jerk that accompanies a falling sensation. During sleep, restlessness centered in the legs, or periodic jerking of the legs can be symptoms of sleep disorders.’
If twitching in your sleep sounds familiar, don’t worry because you are not alone. According to LiveScience, 60-70% of people experience twitching in sleep and that’s only the number of people that manage to remember having these twitches in their sleepy state. Many hypnic jerks can go unregistered.
In terms of science, there are different theories for why twitching in your sleep could occur, but little concrete evidence. Some research suggests that sleep deprivation, and factors such as stress or anxiety, can increase the chances of twitching in sleep. Some people report hypnagogic jerks that are accompanied by the age-old nightmare of falling; which suggests there could be a link to stress.
Although these movements can correlate with certain dreams, such as falling or tripping up, hypnic jerks do not usually reflect what is happening in the dream world. Instead, your brain builds dreams based on what is happening in the real world. In other words, as you twitch or jerk your brain corresponds with your body’s movements and you conjure up a falling scenario in your head. This is similar, to when your alarm clock goes off, and you incorporate the sounds into your dreams.
The BBC suggests that hypnagogic jerks are your last attempts of regaining control as your body drifts off to sleep, stating:
‘As sleep paralysis sets in, remaining daytime energy kindles and bursts out in seemingly random movements. In other words, hypnic jerks are the last gasps of normal daytime motor control.’
One interesting hypothesis behind hypnagogic jerks claims that they occur when nerves ‘misfire’ during the body’s transition from being awake to asleep. Another idea links them back to an ancient primate reflex, suggesting the brain misinterprets the body’s relaxation as a cue that the sleeping primate is about to fall out of a tree, and thus causes the muscles to react immediately.
Hypnic jerks can wake you up suddenly. However, this depends on the intensity of the muscle contraction and will vary massively from person to person. Most people are likely to only experience minor jerks and twitches which are unlikely to wake you up. However, this could cause some annoyance for whomever you share the bed with.
While there is no clear explanation behind twitching in sleep, the above theories suggest that external factors can play a role. If you’ve been suffering from many hypnic jerks recently, the best advice would be to avoid any additional light or sound in your bedroom and try to wake up naturally without an alarm clock. You can also try the following tips:
Exercising too close to bedtime can stop your body from relaxing when it’s time to sleep. Here’s what Healthline had to say on the matter:
In general, if you’re going to exercise at night, it’s best to do light to moderate-intensity activity. This level of activity may help you fall asleep faster and get better quality sleep. It’s also important to complete your workout at least 1 hour before bedtime. If possible, aim to finish at least 90 minutes before you head to bed. This will give your body enough time to wind down.
Caffeine (and other stimulants) are great for keeping you awake, so we recommend eliminating caffeine later on into the day. Here’s what CNBC had to say:
Caffeine can disrupt your sleep up to six hours after consuming it, leading to an hour or more lost in rest, one study found.
So if you want to start winding down and going to bed at 9 p.m., drinking coffee after 3 p.m. is a bad idea. Some health experts recommend people stop drinking coffee as early as 2 p.m.
A highly stressful lifestyle can play havoc with your sleep as you are likely to be more alert, which makes you much more prone to jerks and involuntary muscle twitches. If you’re struggling to reduce stress, check out our podcast on how to sleep when you’re stressed.
Hypnic jerks and twitches are completely normal and quite common. They usually don’t indicate an underlying health issue and are simply a muscle contraction during sleep that ranges from mild to intense. There are many steps that you can take to help relax before bed and a few changes to your bedtime routine can leave you feeling well-rested. Try some of the above suggestions or check out our podcast on How Routine Affects Sleep for advice and tips from Dr. Pixie Mckenna and Professor Kevin Morgan, a Professor of Psychology.