Once diagnosed, neonatal hypothyroidism requires immediate treatment, and the earlier the age at which treatment is started, the better the prognosis. Depending on the cause, some children may need to take medication for life. Neonatal hypothyroidism, also known as cretinism, can lead to symptoms such as umbilical hernia, short stature, mental retardation, growth retardation and low physiological function, and can cause irreversible damage to neurological function. Therefore, once diagnosed, neonatal hypothyroidism requires immediate thyroid hormone replacement therapy. At the same time, the thyroid function should be tested regularly to adjust the dose of medication and to monitor their mental and physical development regularly. After early application of hormone replacement therapy, neonatal hypothyroidism patients can usually grow normally without any significant sequelae, but they must be careful to take the medication as prescribed by the doctor and undergo regular review.