The frequent shaking of the body just after falling asleep may be a normal physiological phenomenon, or it may be caused by calcium deficiency, focal seizures and other reasons. 1. Normal physiological phenomenon: after excessive stress and exertion during the day, shortly after going to sleep, the cerebral nerves do not completely enter the resting state, part of the nerves are still in a state of excitement, which may show that the body frequently shakes violently. 2. Calcium deficiency: some people suffer from calcium deficiency, which leads to low calcium levels in the blood, resulting in increased muscle and nerve excitability, which may lead to frequent and violent shaking of the body just after falling asleep. 3. Focal epileptic seizures: some epileptic patients may experience focal epileptic seizures shortly after falling asleep, which may show frequent violent shaking of the body, and may be accompanied by symptoms such as bruising of the lips and mouth and foaming at the mouth. The frequent violent shaking of the body just after falling asleep may also be related to other factors, and it is recommended to seek medical treatment as soon as possible to confirm the cause of the disease and then give targeted treatment.