Babies waking up once an hour may be due to uncomfortable sleep environment, hunger or overfeeding during sleep, vitamin D deficiency and calcium deficiency. 1. Uncomfortable sleep environment: babies wake up once an hour, may be due to an uncomfortable sleep environment, such as noisy sound, bright light, smell abnormal, etc., will affect the baby’s sleep quality, so that the baby is easy to wake up. 2. Sleeping with hunger or eating too much: babies sleep with hunger, or eat too much before bedtime, stools are not relieved, gastrointestinal discomfort, so there may be an hour of waking up. 3. Lack of vitamin D and calcium deficiency: when the baby lacks vitamin D and calcium deficiency, it is easy to wake up at night and have excessive sweating. The baby wakes up once an hour, there may be other reasons, it is recommended to go to the hospital in a timely manner, improve the examination to clarify the cause of the disease, under the guidance of the doctor to give targeted treatment or treatment.