Neonatal hypothyroidism is not necessarily stupid. After diagnosis, timely supplementation of thyroxine preparation usually has a good prognosis. Neonatal hypothyroidism refers to the insufficient secretion of thyroid hormone in newborns, which is mainly manifested by delayed expulsion of fetal stool, abdominal distension and constipation, prolonged jaundice, low responsiveness to the outside world, low muscle tone, low body temperature, slow respiration, low and scarce crying, and poor peripheral circulation, etc. If not treated in time, it will lead to poor growth in six months and poor mental ability. If not treated in time, low intellectual development and motor development disorders will appear after half a year. If treatment is started as early as possible within 3 months after birth, the prognosis is usually good, and the physical and intellectual development basically reaches the normal level; if the diagnosis is not made in time and the treatment is started after 6 months of life, the growth condition can only be improved, and the intellectual development will be seriously impaired. Newborns diagnosed with hypothyroidism must consult a doctor in a timely manner and be treated actively under the guidance of the doctor.