The pass rate for neonatal hypothyroidism review is very high, about 70% or more. The causes of hypothyroidism in newborns are very complicated, and a large part of the causes are physiological factors, such as stress at birth and infections, etc. These conditions will cause a temporary decrease in thyroid function in newborns, and most of them will adjust themselves to recover as the newborns get older. Therefore, after the birth of a newborn, the test for low thyroid function should be reviewed more often, and most of the newborns will recover after the review. If there is no improvement after repeated checkups, it is basically confirmed that the condition is caused by congenital hypothyroidism, and thyroxine tablets should be used for replacement therapy.