The common clinical causes of infantile screaming include physiological causes such as fright and pathological causes such as vitamin D deficiency and cat-call syndrome. 1. Physiological causes: when infants hear loud noises, they may be frightened or severely stimulated, which may induce them to scream. This is a physiological reaction and parents should avoid the recurrence of this condition. 2. Pathological causes: infants in the process of growth and development of nutritional requirements, if parents for their supplementation of nutrients is insufficient, may cause its body to appear lack of vitamin D, resulting in hypocalcemia, this kind of infants will be more excited at night, but also accompanied by convulsions, abnormal screaming and other symptoms; Cat-call syndrome is a chromosomal abnormality that causes the infant’s larynx to be underdeveloped, resulting in screaming. If the infant’s mental state is normal, it is sufficient to pay attention to observation; if the child has frequent symptoms or abnormal mental state, it is recommended to go to a children’s hospital for consultation and treatment.