Clinical “hyperthyroidism” is mostly seen in “diffuse goiter with hyperthyroidism” and “nodular goiter with hyperthyroidism”, whose main manifestation is increased nerve excitability and high metabolic state. Symptoms of hyperthyroidism are complicated, which can lead to panic, tachycardia, fear of heat, excessive sweating, excessive eating, weight loss, agitation, insomnia, poor concentration, protruding eyeballs, trembling of the hands and tongue, and enlarged thyroid gland. Symptoms of hyperthyroidism in women may also manifest as menstrual disorders or even amenorrhea, and men may have impotence or breast development. At present, the incidence of hyperthyroidism has risen from 1% 10 years ago to 2%, of which 80% of patients are young women. Hyperthyroidism mostly “love” in the white-collar workers, which is related to their physiological structure and face the double pressure of work and life. Early symptoms of hyperthyroidism in women also include easy fatigue, muscle weakness, a few cyclic paralysis, malnutrition, irregular menstruation, decreased menstrual flow, prolonged cycle, and even amenorrhea. Existing treatments for hyperthyroidism are summarized in three ways: oral treatment with internal medicine, surgical resection, and oral treatment with radioactive iodine-131, which simply means “take (internal) medicine, surgery, and drink (iodine-131) water”. Since internal medicine is the basic treatment for hyperthyroidism, many patients are unable to tolerate the pain of long-term medication due to the long treatment time and high recurrence rate. Some patients develop drug allergies and liver damage and are unable to continue treatment. The effect of surgery is similar to that of iodine-131 treatment, but the surgical scars and the risk of surgery discourage many patients, and according to statistics, less than 5% of hyperthyroidism patients in the world are treated by surgery. What about radioactive iodine-131 treatment for hyperthyroidism? What is a radiopharmaceutical? Iodine-131 treatment is safe or not? Below I will address these questions in detail to introduce you to the iodine-131 treatment of hyperthyroidism. Radiopharmaceuticals are drugs containing radionuclides that are used for clinical diagnosis and treatment. With the progress of nuclear technology, nuclear medicine as a new fringe discipline has been rapidly developed, belonging to the field of nuclear medicine, the use of radiopharmaceuticals has also increased accordingly. So, are radiopharmaceuticals harmful to human body? Is it safe to use? This is not only the patient is not clear, even many doctors do not know. As a result, the hazards of radiopharmaceuticals have been overstated in many cases, causing unnecessary psychological burdens for users. In fact, the use of radiopharmaceuticals is very safe, 131 iodine treatment of hyperthyroidism will not bring radiation damage to people, and is not terrible. Radioactive iodine-131 enters the human body, is absorbed by the gastrointestinal tract, and when it flows through the thyroid gland with the blood circulation, it is taken up by the thyroid gland and stays in the gland cells. Iodine-131 releases beta rays, which are concentrated in the gland, and through the biological effect of radiation, the thyroid cells are damaged and destroyed, and some of the cells are necrotic and dissolved, so as to achieve the therapeutic purpose. Since iodine only concentrates in the thyroid gland after entering the human body, and the total amount of iodine in the thyroid gland accounts for 90% of the iodine in the whole body, similarly, radioactive iodine-131 only gathers in the thyroid gland, and the ones that have not been absorbed by the thyroid gland will soon be discharged by the urine and feces, thus it will not cause any damage to other organs, and will only produce a small amount of radiation to the whole body in the process of the blood circulation delivered from the gastrointestinal tract to the thyroid gland. According to experimental research, when the rate of thyroid gland absorbing iodine-131 is 55%, and 131 iodine is given according to the therapeutic dose, the absorbed dose of thyroid gland to the radiation is 15,000 times that of the kidneys, 18,000 times that of the liver, 0.7 million times that of the bone marrow, 19,000 times that of the ovary, and 30,000 times that of the testes; if the rate of absorbing iodine-131 is even higher, then the absorbed dose of the above organs will be even smaller, and it is much lower than the limit value of the radiation protection dose. According to the special investigation, the incidence of thyroid cancer and leukemia after iodine-131 treatment of hyperthyroidism is not significantly different from that of the general population. Since 1942, when the world first used iodine-131 to treat hyperthyroidism, one million cases have been treated abroad and 100,000 cases have been treated in China. In the past, minors with hyperthyroidism were afraid to be treated with 131 iodine, but now the indications for iodine-131 treatment are gradually expanding, and high-dose iodine-131 treatment is also used in foreign countries for children with hyperthyroidism. In recent years, the age limit is no longer mentioned in the indications of iodine-131 treatment in the domestic textbooks of nuclear medicine. Just as any drug has side effects, iodine-131 treatment of hyperthyroidism also has deficiencies, which are only concentrated in the radiation damage to the thyroid gland, i.e., the emergence of hypothyroidism, which is the main obstacle to be overcome by iodine-131 treatment, while radiation damage to other organs is rarely taken into account, because it is rare in practice and theoretically impossible. In conclusion, the use of radiopharmaceuticals is safe, and iodine-131 treatment of hyperthyroidism is a popular treatment method because of its precise efficacy, high cure rate, safety, reliability, simplicity and ease of use. It should be mentioned that radioactive drugs cannot be purchased in general pharmacies and the treatment can only be carried out in the nuclear medicine department of regular hospitals. Regardless of the treatment method for hyperthyroidism, patients should go to regular hospitals, and should not blindly follow advertisements or gullibly believe in the peddlers and doctors, so as to avoid delaying the treatment.