Endemic cretinism, including endemic subclinical cretinism, is a neuropsychiatric syndrome caused by iodine deficiency and characterized by intellectual disability. When the iodine deficiency in the area is fully corrected, endemic cretinism or subclinical cretinism can be prevented. Typical endemic cretinism generally occurs in severely iodine-deficient areas where endemic goiter is prevalent. Children in the area will almost certainly develop endemic cretinism if their urine iodine is less than 20µg/L. When the enlargement rate of endemic goiter is greater than 30%, there will usually be an epidemic of endemic cretinism. Endemic subclinical cretinism occurs in all iodine-deficient areas, but is more common in moderately or severely iodine-deficient areas.