12-year-old children always wake up in the middle of the night, may be due to environmental influences and other physiological factors, as well as calcium deficiency, gastrointestinal diseases and other pathological factors. 1. Physiological factors: 12-year-old children always wake up in the middle of the night may be due to the sleeping environment is noisy or bright light and so on. 2. Rational factors: calcium deficiency and gastrointestinal diseases can also cause 12-year-old children to wake up in the middle of the night. Calcium deficiency can lead to increased excitability of the cerebral cortex, usually manifested in the middle of the night always wake up and other symptoms; enteritis and other gastrointestinal diseases may lead to 12-year-old children in the middle of the night abdominal pain, abdominal distension and other conditions, which leads to children always wake up the situation. 12-year-old children always wake up in the middle of the night, there may be other reasons, it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.