At some point in our lives, we have all experienced the feeling of falling, that rush of blood you get as you plummet to the Earth. It might be from jumping into a swimming pool, going on a rollercoaster, or for the adrenaline junkies amongst us when you skydive.
However, whether you’ve done it for pleasure or not in the past, the one time we’d all like to experience it is when we are asleep.
We’ve all felt it though, just as you drop off, you experience that same loss of control which promptly jolts you awake.
What Is It?
This odd sensation is known as the “hypnic jerk” and it occurs when your muscles involuntarily contract quickly, almost like a twitch or spasm.
Unfortunately, there is no certain reason behind this odd phenomenon, however, if we take an evolutionary perspective, some sense can be made of it.
One suggestion, which still makes sense today, is that it is an instinctive reaction which allows us to check the environment we have fallen asleep in to check that it’s safe one last time.
Another, which is certainly reserved for our distant ancestors is that it helped us check the stability of our body position before falling fully asleep, especially whilst in trees.
There is another theory which doesn’t focus on evolutionary survival tactics, and instead, suggests it has more to do with a physiological battle.
It suggests that the hypnic jerk is a symptom of our active psyche giving into the sleep process, and the jerk is a sign of initial reluctance.
If you prefer to subscribe to this theory, the best way to understand it is to think of the jerk as a sign that our brain is switching from an active state to a more relaxed state of paralysis.
When Hypnic Jerks Go Wrong
No matter the reason why we do it, there’s no doubting the initial fright it gives us, a fright which is sometimes a lot worse than others.
Some people can experience quite severe jerks which keep them awake, essentially preventing them entering the normal sleep process. In extreme cases, this can lead to a form of sleep-onset insomnia.
The hypnic jerk is essentially connected to your internal motor because it is a muscle spasm. What this means is it can be influenced by certain stimulants, ultimately making them more frequent.
Caffeine is a big stimulant, and among the many reasons why you shouldn’t consume caffeine before bed, this is certainly another.
Heightened stress levels and anxiety are also associated with an increased risk of hypnic jerk, so if it is something that is bothering you, it is worth questioning if you might be suffering from either.
Like many sleep issues, its other associations include sleep fatigue, having an erratic sleep schedule or being consistently overtired. So, having a regular and healthy sleeping pattern should help.
While there have been no official studies into this, experiences have proven that diet could exacerbate these jerks. It is thought that having deficiencies in magnesium, iron or calcium can increase your chances of experiencing them.
It’s also thought that you may have a heightened chance of experiencing this if you sleep somewhere with constant sensory distractions, for example, if you sleep in the same room where there might be unnecessary light or noise.
Because the hypnic jerk is a widespread but largely harmless phenomenon, there has never been much cause to explore it with any further research. Something we do know is that the older we get, the less we generally have.
However, if you regularly suffer from them and can seem to understand why, it is important you do contact a medical professional for advice, as it may link to a wider health or sleep issue, like sleep apnoea.