Why do we feel like we're freefalling before we go to sleep?

You know that feeling when you're just falling asleep, and then you feel like you're falling – and you're body jumps? You are not alone – it happens to 70% of people – even the healthiest – and we are here to explain why.

This phenomenon is called myoclonus (myo = muscle, clonus = contraction) and it is basically a short, sudden and involuntary movement of a muscle or group of muscles. Hiccups are a common form of myoclonus. Contraction of the muscles is called positive myoclonus; relaxation is called negative myoclonus.

Your mind is just trying to make sure you're okay

One theory that tries to explain why this happens is that sleep at this early stage is so light that the brain mistakenly interprets it as a state of wakefulness, but it also recognizes that the muscles are not moving. The brain sends a signal to the muscles to make sure everything is working properly. The message is sent through the nerves and causes a contraction which is interpreted as movement, and many times feels like a fall.

What factors are involved?

There are many factors that may increase these events – usually, the same factors that cause sleep disturbances. If we reduce these disturbances, we may improve the quality of sleep:

1. Mental stress – when we are under stress, it is more difficult to fall into a deep sleep. This may cause a disturbance in the sleep cycle.
2. Use of drugs and alcohol – here, too, there will be a disruption to the sleep cycle, which will remain lighter without reaching the dream stage. 
3. Caffeine – drinking a lot of coffee or consuming other products containing caffeine will, of course, cause sleep disturbance. But it may also cause muscle contractions that bring about the same events of myoclonus.
4. Lack of sleep – this will cause a disturbance in the sleep cycle and may result in more myoclonus events than usual.

Myoclonus rarely indicates a deeper health problem. In rare cases it may be a manifestation of a neurological problem, such as epilepsy, or a metabolic problem, such as an adverse reaction to a drug taken. 

In any case, if the occurrence of the events becomes frequent and consistent, it may be wise to contact a doctor in order to find out the cause and get the appropriate treatment.