Sudden shaking of the body after falling asleep may be a physiological phenomenon, or it may be caused by calcium deficiency or epilepsy. 1. Physiological phenomenon: If there are recent cases of overwork, mental stress, cold, etc., it may cause the symptom of sudden shaking of the body after falling asleep, which is a normal phenomenon and can be improved by relaxing and resting and keeping warm. 2. Calcium deficiency: the elderly, children, pregnant women are particularly prone to calcium deficiency, calcium ions can mainly maintain muscle excitability, calcium deficiency is prone to cause muscle spasms, resulting in limb shaking, can be relieved through medication calcium. 3. Epilepsy: Epilepsy is caused by abnormal discharges in the brain, causing involuntary twitching of the limbs or body. In this case, it is recommended to do an EEG to clarify whether there is epilepsy or not, and the symptoms can be relieved by antiepileptic drugs. Sleeping body suddenly shaking, should go to the hospital for medical treatment, can be combined with other clinical symptoms as well as examination comprehensive diagnosis.