The causes of crying in newborn babies include physiological factors such as improper feeding, as well as pathological factors such as colic and vitamin D deficiency. 1. Physiological factors: noisy environment, inappropriate temperature, hunger, before and after urination and defecation, as well as improper feeding, etc., may cause newborn babies to cry. 2. Colic: Breastfed children with lactose intolerance, artificially fed children with protein allergy, etc., as well as indigestion may trigger colic in children. As the pain level is more intense, the baby manifests itself in crying that is difficult to appease. 3. Vitamin D deficiency: These infants are often accompanied by occipital baldness, night sweats and square skulls. Early prominent manifestations are night terrors and crying. There may be other reasons for newborn babies to cry, so it is recommended to go to the hospital in time to improve the examination to clarify the cause of the disease, and then give targeted treatment or treatment.