Sudden shaking during sleep is usually called Prosopagnosia, which is a common physiological phenomenon, but may also be caused by hypocalcemia, epilepsy and other diseases. 1. Prosopagnosia: Sudden shaking of the body during sleep, accompanied by a feeling of free fall or a feeling of stepping in the air, is generally due to abnormal excitation of the motor nerves, causing transient contraction of the muscle groups, may be related to overwork, excessive exercise before bedtime, generally has no adverse effects on the body. 2. Hypocalcemia: Low blood calcium level may also lead to shaking during sleep, mainly due to calcium deficiency in hypocalcemia, neuromuscular excitability increases, and muscle spasms and twitching may occur. It is recommended to take active treatment of calcium supplementation and review the blood calcium level regularly. 3. Epilepsy: Sleep-type epilepsy may also present with shaking during sleep, which is usually accompanied by double eye rolling and loss of consciousness. It is recommended to consult a doctor for an EEG and other tests. Sudden shaking during sleep may also be related to other factors, and if accompanied by obvious discomfort, it is recommended to consult a doctor as soon as possible.