Ten-month-old babies crying in their sleep may be caused by physiological reasons such as fright, or it may be caused by vitamin D deficiency, upper respiratory tract infections and other reasons. 1. Physiological reasons: the child is frightened during the day, not enough food before bedtime to lead to hunger at night, as well as the sleep environment is noisy and other reasons can lead to the baby sleep crying. You can take measures such as feeding, calming the baby, and maintaining a good sleep environment to ease the baby’s crying. 2. Vitamin D deficiency: Vitamin D deficiency is often easy to combine with low calcium, the baby performance irritability, crying, but also with easy to startle, excessive sweating, occipital baldness, sleep disturbance. Therefore, vitamin D deficiency babies always cry in their sleep. 3. upper respiratory tract infection: upper respiratory tract infection will cause increased respiratory secretions, causing the child to cough, cough phlegm, sleep will be due to phlegm blockage of hypoxia and respiratory difficulties, resulting in the baby woke up at night due to physical discomfort and crying. Ten-month-old babies sleep crying for more reasons, including acute gastroenteritis, eczema, improper feeding and other reasons. Parents should take their children to the hospital in a timely manner, complete the examination, and give targeted treatment after clarifying the cause of the disease.