Recurrence of hyperthyroidism can usually be treated with iodine 131 under the supervision of a doctor. The treatment of hyperthyroidism includes three kinds of treatments: (1) anti-thyroid medication; (2) iodine 131 treatment; and (3) surgical treatment. Iodine 131 is recommended to treat hyperthyroidism when there is allergy to oral antithyroid medication or serious adverse drug reactions, combined liver injury, relapse after antithyroid medication or surgical treatment, or thyroid enlargement of more than two degrees. Therefore, recurrence of hyperthyroidism can be treated with iodine 131 under the guidance of a doctor. Generally, the effect is obvious in about 1 month of treatment, and the thyroid function of more than 60% of the patients returns to normal in 3~4 months of treatment. For patients whose hyperthyroidism is not relieved after 3 to 6 months of iodine 131 treatment, another iodine 131 treatment may be recommended. In conclusion, patients with recurrence of hyperthyroidism are advised to go to the Department of Endocrinology or the Department of Nuclear Medicine to choose the appropriate treatment plan according to their own conditions.