A 5-year-old child crying in the middle of the night for no reason may be caused by physiological factors, calcium deficiency, gastrointestinal discomfort and other factors. 1. Physiological factors: for example, by the shock, will be in the night time sleep crying for no reason, parents should be timely to appease the child, so that the child’s mind is stable, may be on their own to return to normal, do not need to carry out other treatments. 2. Calcium deficiency: 5-year-old children partiality picky eating, resulting in a lack of calcium in the body, will cry at night for no reason, may also often appear leg cramps, more out of the sun, to avoid affecting the development of the body. 3. gastrointestinal discomfort: for example, indigestion, intestinal obstruction, intestinal spasm, etc., may cause abdominal pain and other symptoms, which will lead to the child crying in the middle of the night for no reason, may also be accompanied by nausea and vomiting. 5-year-old children crying in the middle of the night for no reason, there may be other reasons, it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.