The causes of children waking up crying in the middle of the night include vitamin D deficiency rickets, other diseases, hunger and so on. 1. Vitamin D deficiency rickets: the clinical manifestations of this disease in the active phase include waking up in the middle of the night and crying, etc. Blood vitamin D level should be examined, chest X-ray, etc. to make a clear diagnosis, and supplemental vitamin D treatment can be given, calcium supplementation can be given, and at the same time, more sun exposure to promote the absorption of vitamin D and calcium. 2. Other diseases: for example, upper respiratory tract infection, acute gastroenteritis, children will be uncomfortable at night, there may be the possibility of waking up at night crying, then we should actively treat the original disease. 3. Hunger: when children are hungry, the above situation may also occur, soothe the child’s emotions, and then eat. Children waking up crying in the middle of the night, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to determine the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.