Children may wake up crying in the middle of the night with too much excitement before going to bed, frightened during the day, lack of vitamin D and so on. 1. Too much excitement before going to bed: children play too much before going to bed, too excited, easy to cause the child sleep is not solid, the middle of the night to wake up and cry. 2. Being frightened during the daytime: the child is subjected to adverse stimuli during the daytime, such as fright, which will also affect the child’s sleep at night. 3. Lack of vitamin D: the lack of vitamin D in the child’s body is likely to cause night crying, sweating while sleeping and other symptoms. There may be other reasons for children to wake up in the middle of the night and cry, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, and then under the guidance of the doctor’s treatment.