The baby is always crying at night before going to bed may be physiological factors, but also may be the manifestation of certain diseases, such as indigestion, nervous excitement, lack of vitamin D and other conditions lead to. 1. Physiological factors: if the baby’s sleep environment is abnormal, the environment temperature is relatively high or low, it will lead to the baby can not enter the sleep, this time will also produce crying. 2. Pathological factors: (1) indigestion: if the baby eats too much food before sleep, the accumulation of food will cause indigestion, which will lead to accumulation of food, the baby’s abdomen is uncomfortable before sleep, and will often produce crying. (2) lack of vitamin D: if the baby usually do not pay attention to diet, there are picky eaters, at this time will also be easy to cause the baby’s body lack of vitamin D, will not only lead to the baby to fall asleep difficult, the baby before sleep will also appear to cry. Excluding the influence of physiological factors, it is recommended to take the child to the hospital to check the cause of the disease, according to the condition to take targeted treatment methods to treat.