Newborn screening includes four main disorders, glucose 6 phosphatase deficiency, adrenocortical hyperplasia, congenital hypothyroidism, and phenylketonuria. Newborn screening is mainly about congenital inherited metabolic disorders that require the accumulation of abnormal metabolites and therefore requires the collection of plantar blood for screening three days after the baby is born and after adequate breastfeeding. Congenital hypothyroidism is caused by a deficiency of thyroid hormones, which manifests itself in the form of delayed mental development, short stature of the limbs, facial and lower limb edema, etc. Phenylketonuria is caused by a deficiency of phenylalanine hydroxylase in the baby’s body, which also manifests as mental retardation, abnormal psychological behavior, yellow hair, and rat urine smell. Congenital adrenocortical hyperplasia is also a genetically induced disorder that manifests as salt loss syndrome, androgen excess syndrome, and glucose 6 phosphatase deficiency mainly causing severe jaundice and anemia.