Age: Extensive clinical practice both at home and abroad has demonstrated that 131 iodine is safe and effective in the treatment of hyperthyroidism in adolescents and children. Although the available data indicate that 131 iodine treatment for hyperthyroidism is non-carcinogenic and does not cause reproductive abnormalities, the survival period of pediatric and adolescent patients is long, and there is still limited information on long-term (60-70 years) follow-up studies after 131 iodine treatment, so further evaluation of the potential long-term risks is needed. Most scholars believe that adolescent and pediatric patients who are allergic to antithyroid medications, or who have poor efficacy or significant toxic side effects with thyroid medications, or who have relapsed after treatment with antithyroid medications, or who have more pronounced goiter, may be treated with 131 iodine.