Just as I was about to fall asleep, I suddenly trembled

When we are sleeping, since the brain nerves are still not completely quiet, all kinds of wonderful dreams will always happen. We usually dream because the cerebral cortex is active, displaying various thoughts in our brain. Sometimes, we may feel that we suddenly shake while sleeping, and that feeling is like weightlessness, and we may feel insecure. So, what was the reason why the body suddenly shook?

There are two main theories about hypnic jerks, based on neuroscience and evolution.

1. The most common explanation is that when you fall asleep, two different systems in your brain are fighting each other. When you become somewhat sleepy, system 1 usually hands over control to system 2 and the sleep jerks stop, so they are thought to be the result of a struggle between sleep and wakefulness that occurs in the body every time you try to fall asleep.

2. Another way of saying it is that after falling asleep, the body's muscles should be relaxed. However, due to sleeping posture, daytime fatigue, excitement, irritability and other reasons, some people's muscles are not completely relaxed after falling asleep, and they enter the "rapid eye movement stage" when dreaming. Especially when the dreams are too vivid, they stimulate the brain's central nervous system to send signals, which will produce small movements and act out the dreams.

Generally speaking, a sudden shake of the body while sleeping is mostly a normal physiological reaction. It is a phenomenon caused by nervousness, stimulation, or excessive work fatigue, which causes the whole body or local muscles to twitch suddenly. The time is very short, like an electric shock, and the feet will suddenly kick.

However, it can also be caused by pathological muscle cramps. This phenomenon mainly occurs due to the following reasons:

1. High pressure. At work, people who have tense relationships, heavy tasks, long periods of overtime, often stay up late, and have poor sleep quality are prone to this symptom. People who get angry easily or are easily frightened may also experience this symptom.

2. Severe calcium deficiency. Low calcium levels cause the muscles and nervous system to become more excited, leading to muscle spasms and nerve contractions.

3. Weak liver and kidney, insufficient qi and blood. If the frequency is not very high each time, it may be caused by weak liver and kidney and insufficient Qi and blood.

4. Symptomatic muscle cramps: If accompanied by headache, dizziness and other conditions, it is also pathological and you should go to the hospital in time for a brain CT or MRI to rule out brain diseases.