Pretty much everyone has experienced this bizarre phenomenon. You are sleeping peacefully, trying to rest before another day of work. But suddenly, you entire body jerks, you feel like you are falling and wake up with your heart beating very fast. Sometimes the hypnic jerk, which is how this phenomenon is called, is so strong you wake up covered in sweat. But why does it happen?
Interestingly enough, despite the fact that hypinc jerk is relatively common, scientists don’t know exact reasons. Hypnic jerk is so common we can safely say that most people have experienced it at least once in their lifetime. And yet we don’t know why, but scientists have been trying to solve this puzzle. It has been noticed that hypnic jerk, also known as sleep twitch or myoclonic jerk, is more common between people with irregular sleeping schedules and between those suffering from anxiety. You are also more likely to experience it sleeping in a new place, on an uncomfortable bed, being nervous about tomorrow, tired from stress and so on.
Scientists have noticed that our closest primates experience something like hypnic jerk. That is quite interesting and could indicate causes being evolutionary. In fact, one hypothesis states that hypnic jerk is our natural protection from unplanned sleep. Nowadays just dosing off is no big deal (unless you are driving), but millions of years ago it could have meant death by falling out of tree. Scientists from University of Colorado think that hypnic jerk could be our self-protection mechanism, requiring us to re-check our sleeping position, making sure it is safe. This hypothesis is supported by the fact that hypnic jerk is often followed by a falling sensation.
Hypnic jerk is more common between children of 8-12 years old. Later it becomes less and less frequent, but some people experience several jerks before finally falling asleep peacefully. This phenomenon typically occurs during the non-rapid eye movement sleep cycle. If you go to sleep earlier, your body may interpret it as an unplanned rest and may wake you up to re-evaluate the situation. However, whatever are the causes, hypnic jerk doesn’t really save people – don’t count on it waking you up in situation when you’re too tired to stay awake.
There are ways to reduce the frequency of hypnic jerks. First of all, you should maintain a regular sleeping schedule. Make sure your bed is comfortable and try to calm down before going to sleep. Don’t do anything that makes you stressful and, if possible, forget about anxiety of tomorrow. Finally, avoid caffeine and strenuous activities in the evening.