Children drooling after sleeping suddenly twitching limbs may be epilepsy, but does not rule out the possibility of febrile convulsions, vitamin D deficiency and so on. Epilepsy is a sudden, brief, recurrent seizures of chronic brain diseases, pediatric typical main symptoms for the seizure of the two eyes straight, staring forward, foaming at the mouth, limbs twitching or straightening, the throat will also emit a strange sound, so the child drooling after sleep suddenly twitching limbs may be epilepsy. But in addition to epilepsy, febrile convulsions, vitamin D deficiency and other diseases can also lead to children drooling after sleep suddenly limbs twitching. Febrile convulsions are mainly caused by an increase in body temperature, and the child will have stiff limbs and shaking, eyes staring, squinting or upturned, and head tilted back. Vitamin D deficiency is caused by vitamin D deficiency, prevalent in children, mainly due to insufficient sunlight, insufficient vitamin D intake, etc. It may lead to vitamin D deficiency tetany, manifested as convulsions, hand and foot twitching, laryngeal spasm, etc.. There are many reasons why children drool and suddenly twitch their limbs after sleeping, so we suggest that family members bring their children to the doctor for relevant examinations.