Newborn sleep disturbance or crying is a relatively common problem, newborns suddenly cry when they sleep, the reasons are many. 1, because the neonatal nervous system is not well developed, nerve excitation may occur suddenly during sleep, and it will be manifested as crying. 2. Newborns generally need to be fed once every 2-3 hours with a small amount of milk. If the child is suddenly hungry, the child may cry if the adult cannot perceive it. 3, frightened or hear a relatively loud sound, the baby will also suddenly cry during sleep. 4, vitamin D deficiency rickets can also lead to baby sleep difficulties, easy to wake up after sleep, crying, easy to startle and other performance. If the above factors are ruled out, the baby’s sudden crying at bedtime may be caused by disease factors, and the baby should be observed for symptoms such as fever, rash, abdominal pain and breathing difficulties. If your baby cries suddenly at bedtime because of physiological factors, parents can deal with it on their own and find out the cause to remove it; if it is caused by disease factors, it is recommended to take your baby to the hospital to determine the cause and deal with it symptomatically.