Congenital hypothyroidism, also known as cretinism, is a disease that must be detected and treated early to avoid brain developmental damage leading to mental retardation, and is treated by taking levothyroxine sodium, thyroid tablets, and other medications to supplement thyroid hormones under the guidance of a doctor, and requires lifelong medication, and the dose of medication must be adjusted as the age increases, so you cannot stop or adjust the dose of medication at will. After regular treatment, thyroid function and bone age should be reviewed regularly. Generally, if treatment is started within 3 months, most of the intelligence can reach the normal level; if treatment is started after 6 months, although growth can be improved, intelligence development may be impaired. It is best to breastfeed during infancy. As the child grows up, it is important to gradually increase the amount of nutrient-rich and easily digestible foods such as protein, vitamins and minerals in the diet.