Iodine 131 treatment is mainly used for diseases such as hyperthyroidism or thyroid cancer. After the physician’s evaluation to exclude contraindications, the appropriate dose of iodine 131 solution or capsule is taken to kill the thyroid tissue or cancer cells by short-range radiation of beta rays. Prior to Iodine 131 treatment, a detailed thyroid-related examination should be done, which is mainly used to assess the size of the thyroid gland and the iodine uptake rate of the thyroid gland, etc., in order to formulate the appropriate dose of Iodine 131. According to the prescribed dose, the medication should be taken at the relevant window of the hospital. After taking the medication, you should pay attention to rest, pay strict attention to any adverse reactions, eat a light diet, etc., and strictly follow the procedure during the treatment. It should be noted that if you are pregnant and lactating women, or plan to get pregnant within six months, you are not suitable for iodine 131 treatment, so as not to cause damage to the thyroid gland of the fetus. For patients with moderate-to-severe proptosis or those suspected of malignancy, thiourea drugs and surgical treatment should be preferred; if neither of them can be carried out, iodine 131 treatment can be considered under multidisciplinary collaboration. Consult the doctor promptly if there is any discomfort.