Baby crying at night and not sleeping well may be caused by hunger, need to change diapers, emotional stimulation, infantile colic, rickets and other reasons. 1. Hunger: when the baby is too small, drinking milk once can last about 2~3 hours, when the baby cries at night and can’t sleep well, it may be caused by the stomach hunger and need to eat milk, parents should feed the baby in time. 2. Need to change diapers: baby urine and feces will lead to wet diapers, will make the baby’s buttocks feel uncomfortable, which will lead to the baby crying at night to sleep, parents should give the baby timely replacement of dry diapers. 3. Emotional stimulation: If the external environment is too noisy, uncomfortable clothes, too hot or too cold environment, may also lead to the baby crying sleep, parents should be based on the baby’s environment, increase or decrease clothing or quilt. 4. Infantile colic: infantile colic is mostly caused by upper respiratory tract infections, parasitic infections and other causes, the child will have acute abdominal pain, when abdominal pain is severe and occurs at night, it will lead to the baby to cry and sleep unsteadily 5. Rickets: rickets is mostly caused by the lack of vitamin D, the patient will appear calcium deficiency, which will lead to increased neural excitability, resulting in children difficult to sleep and accompanied by crying, hyperactivity symptoms. If the baby appears to cry at night, parents should check the baby’s body changes in time, because the baby is too small to express, parents should observe the baby’s changes more often, and if there is any abnormality should go to the hospital in time for medical treatment.