1. Before taking iodine-131: 1. Anti-thyroid drugs such as methimazole, propylthioxypyrimethamine and thyroid hormone preparations (such as thyroxine tablets, eugenol, gahan, etc.) must be stopped for at least 1-2 weeks before treatment. 2. Low iodine diet: 1-2 weeks before iodine treatment, no large amount of iodine-containing foods such as seafood such as kelp, seaweed, sea shrimp and crab, and large amount of salted vegetables, etc. No use of iodine-containing contrast agents and hormone preparations, iodine-containing Chinese and Western medicines. 3.No consumption of beverages containing Charcoal before treatment. 4.Hematological examination such as blood routine, liver and kidney function, thyroid function, etc., and other examinations are required for serious cases. 5.Iodine uptake of thyroid gland should be measured, and fasting is required before measurement. Generally, it is necessary to check at least 2 time points (2-3 hours and 24 hours after taking iodine 131 in our department). 6. At present, in China, most of the iodine 131 treatment for hyperthyroidism is outpatient treatment and does not require inpatient treatment. It is a chronic disease, and generally outpatient medical insurance and insurance companies can pay for it according to the regulations. 7. Note that women of childbearing age should be aware that iodine treatment cannot be administered during pregnancy or breastfeeding. If there is suspicion during menstruation, you must inform the attending physician, and for suspected pregnancy, you must exclude the possibility of pregnancy. 8. Those who have hyperthyroidism combined with other diseases should also inform the attending physician. After taking iodine-131: 1. Do not eat 2 hours after taking iodine. In order not to affect the absorption of the drug. Those who suffer from motion sickness can stop for 2 hours before riding in a car, or take motion sickness medicine. 2. After taking iodine-131, be careful not to eat foods high in iodine. 3.After taking iodine 131, avoid eating spicy and stimulating food as much as possible. Drink as little alcohol as possible. 4. In order to reduce the risk of hyperthyroidism proptosis, you need to quit smoking. 5.After taking iodine 131, those who need to take other drugs according to doctor’s orders, especially glucocorticoids (such as prednisone, etc.), must follow doctor’s orders. 6.After iodine treatment, if you have high fever, significantly faster heartbeat, or significantly more frequent urination or defecation, you should contact your doctor or go to a large general hospital nearby, and bring the treatment information with you. 7. After taking iodine 131, there will be different degrees of radioactivity in the body. At this time, it is necessary to pay attention to minimize the radiation to people around you, such as taking a vacation at home, avoiding close contact with others, etc. 8. For those who are preparing for pregnancy, it is recommended to prepare for conception after six months of iodine treatment and when the nail function returns to normal.