A 5-year-old child waking up in the middle of the night and crying all the time may be caused by a lack of calcium, being frightened, or dietary problems. 1. Calcium deficiency: Night terrors caused by a lack of vitamin D and calcium will not only cause crying at night, but also waking up in the middle of the night, chicken breasts, funnel chests, and ectopia of the rib margins. 2. Suffering from fright: because the child is frightened by accidents during the day or is emotionally unstable, he/she sleeps uneasily at night and cries at night. 3. Dietary problems: children will have nocturnal bloating, abdominal pain, intestinal cramps and other symptoms at night, mainly because children’s diet is too much and too mixed, which leads to children’s crying at night. If a 5-year-old child has the symptom of always waking up and crying in the middle of the night, he or she should go to the hospital as soon as possible to avoid delaying his or her condition.