The feeling of falling when sleeping is known as a hypnagogic jerk, night start, hypnic jerk or sleep twitch. It is a common event, with about 70% of people experiencing it from time to time. Below we delve more into hypnic jerks, what causes it and when they should become a cause for concern.
Hypnagogic jerks can be defined as involuntary muscle twitches in the arms, legs or even the whole body that occur just as someone is beginning to fall asleep, jerking them awake. They are accompanied by quickened breathing and sweating, as well as a strange feeling of shock co-occurring with a falling sensation. These jerks could be seen like acting out a dream, for instance, falling off a cliff or even tripping.
Sleep twitches occur during the non-rapid eye movement cycle. They are more common in childhood. An 8 to 12-year-old child could experience 4 to 7 twitches an hour. They decrease with age to about 1 to 2 per hour by ages 65 to 80.
There are many hypotheses about the causes of the feeling of falling while sleeping. The most common and broad reasons are:
- High caffeine intake
- Sleep deprivation
- Strenuous activity in the evening
- Irregular sleeping schedules
- The slowing down of the nervous system
When you begin to fall asleep, your nervous system naturally begins to slow down. The breathing and heart rates also slow down, there is a shift in muscle tone and there is a drop in body temperature. Night starts occur during this transition from awakeness.
- Brain misinterpretation
According to this theory, as you begin to fall asleep, the brain can interpret the muscular relaxation as actually falling. It, therefore, alerts the nervous system causing your muscles to tense up, in a bid to protect you from “falling”.
Closely related to the above hypothesis is the view that hypnic jerks could be a reflex response to the brain misinterpreting muscular relaxation as a sign that our ancestor primates are actually falling from a tree. The reflex action could also have been caused by some effort to readjust sleeping positions to avoid a fall when sleeping in a nest or branch. This reflex response seems to have been carried over from our ancestors to modern day generations, centuries later.
- Discrepancies between our physical and astral bodies
According to this hypothesis, there are two “phases” of our bodies: the physical and astral. When we are awake, there is synchrony between the two bodies, thus they stay aligned. When we sleep, there is disengagement, with the astral body disengaging from its physical counterpart. Our “energies” is what keeps the two bodies connected. When we sleep, our bodies relax, expanding the energies. This is what causes the aforementioned disengagement.
While our physical bodies need sleep, our consciousness does not. The latter usually has different lucidity levels at all times. Most of us lose lucidity when we sleep. If you sleep but your consciousness maintains lucidity, you experience astral projection (where the astral body floats near the physical body). During astral projection, most people do not have lucidity. If you do regain lucidity during an out of the body experience, you feel like you are falling when sleeping.
Since the brain tries to incorporate stimuli and sensations to our dreams, it explains why we tend to have dreams associated with falling during hypnagogic jerks, for instance falling into an abyss. This happens during the rapid eye movement cycle of sleep.
Our brain’s interpretation of sensations becomes fuzzy when we are asleep. If you regain lucidity during an astral projection, your brain interprets floating as falling.
When do sleep twitches become a concern?
Usually, sleep twitches should not be a cause for concern. If you are awoken from your sleep by a hypnagogic jerk, rolling over and sleeping will take care of the experience. Taking care of the factors that cause or worsen night starts (caffeine, stress, and the other above-mentioned factors) should be the other measure that you take. You can also use relaxation techniques to help your body’s systems to slow down.
You need to see your doctor if hypnic jerks or the associated anxiety cause you not to get enough sleep. They will help you to practice relaxation techniques that will make your body comfortable with astral projections, and not get shocked when they do happen. They can also help you know how to get out of these out of the body experience.