The main causes of sleep convulsions are overfatigue, epileptic seizures, hypocalcemia and so on. 1. Excessive fatigue: If the patient is overworked during the day, the lactic acid in the lower limbs accumulates in large quantities, and there is a possibility of soreness and convulsions when sleeping at night. Usually it will return to normal after proper rest. 2. Epileptic seizures: patients with a history of epilepsy or epilepsy secondary to organic brain lesions such as acute cerebral hemorrhage, cerebral infarction and other diseases, the patient will show limb convulsions, and some of the patients will also be accompanied by impaired consciousness, foaming at the mouth, and clenching of the teeth and other symptoms. 3. Hypocalcemia: Calcium is an important element in the human body, and it is an important component of bones, teeth and other structures. Calcium plays an important role in regulating muscle contraction and cardiac electrophysiology. When the patient low calcium will cause nerve cell excitability increase, showing the phenomenon of lower limb twitching, perfect electrolyte examination can be clearly diagnosed. The cause of sleep twitching is very complex, need to be combined with the patient’s accompanying symptoms to improve the relevant examination to clarify the cause of the disease, so as to systematic treatment, it is recommended to go to the hospital.