The baby’s crying during sleep may be related to physiological factors, or it may be caused by indigestion or calcium deficiency. 1. Physiological factors, if the baby is urinating during sleep, hungry, or the baby has other discomforts, it may lead to the symptoms of crying in sleep. 2. Indigestion, if the baby has indigestion, the accumulation of food in the digestive tract, may lead to abdominal distension, affecting the baby’s body, such symptoms. 3. Calcium deficiency, if the baby’s body lacks calcium, it may lead to increased nervous system excitability, so it is more likely to appear this symptom, accompanied by sweating, occipital baldness and other reactions. The baby sleeps and cries, 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.