Tossing and turning in the sleep of 9-year-old children is a sign of poor sleep quality, which should be considered to be caused by psychological factors, indigestion, calcium or vitamin deficiency, etc. 1. Psychological factors: 9-year-old children will also face pressure in life or study, when children’s ability to resolve psychological pressure is weak, the phenomenon of poor night sleep will occur. 2. Indigestion: If they have eaten too much before going to bed or have indigestion in their daily life, the indigestion may lead to stomach upset during sleep and poor sleep quality. 3. Calcium or vitamin deficiencies: Calcium or vitamin deficiencies can affect the normal metabolism of substances in the child’s body, affecting the nervous system or skeletal muscle system, resulting in poor sleep quality. Sleep plays an important role in children’s normal growth and development. Children with poor sleep quality should be corrected in time, and parents should take their children to the hospital if necessary.