Hyperthyroidism (hyperthyroidism) is a very common endocrine disease. In recent years, there has been an increase in the number of patients with hyperthyroidism, and according to surveys in some provinces and cities, the incidence of hyperthyroidism has been as high as 10%, and the incidence is even higher in coastal areas. As the patient’s thyroid cells are overactive, they produce too much thyroid hormone, which leads to accelerated metabolism, resulting in a variety of symptoms. Typical manifestations are a large neck (goiter), protruding eyes, eat more, drink more, but people become thin, thin symptoms than diabetic patients are also obvious. Some people are thin but energetic, often “excited” to sleep at night, accompanied by irritability, fear of heat and sweating. Female patients often have scanty menstruation, prolonged cycle or even amenorrhea. Most of the patients have the above symptoms for 2-3 months before attention is drawn to it. If there are unexplained short-term weight loss, rapid heartbeat, fear of heat and excessive sweating, women’s menstrual disorders, amenorrhea and so on, hyperthyroidism should be considered as a possibility, and should be timely to the hospital for medical treatment. If hyperthyroidism is not properly treated or remains untreated for a long period of time, it will cause damage to the function of many systems of the human body, and hyperthyroidism will be associated with a variety of diseases, especially endocrine system and cardiovascular system diseases are the most common. Iodine-131 treatment for hyperthyroidism is a very effective method. Thyroid cells have a special affinity for iodide, and after taking a certain amount of iodine-131 orally, it can be absorbed by the thyroid gland in large quantities. Iodine-131 can selectively destroy the thyroid follicular epithelium in thyroid tissues without affecting the neighboring tissues, and thyroid tissues can be subjected to prolonged centralized irradiation, and the glands can be gradually necrotic after being destroyed, and replaced by non-functional connective tissues, so as to reduce the secretion function of the thyroid gland to cure hyperthyroidism and achieve a similar effect as that of hyperthyroidism. Hyperthyroidism can be cured, to achieve similar to the purpose of sub-total thyroidectomy. Therefore, some people call iodine-131 treatment of hyperthyroidism “internal thyroid surgery”. The effective rate of radioactive iodine-131 treatment for hyperthyroidism reaches more than 90%, and about 50%~80% of the patients are cured in one course of treatment. Is Iodine-131 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 harm of radiopharmaceuticals has been over-exaggerated in many cases, causing unnecessary psychological burdens on users. In fact, the use of radiopharmaceuticals is very safe, and the treatment of hyperthyroidism with iodine-131 does not cause radiation damage and is not scary. Iodine-131 only accumulates in the thyroid gland, and what is not absorbed by the thyroid gland is quickly excreted by the urine and feces, thus causing no damage to other organs, which is much lower than the national radiation protection dose standard. Moreover, radioactive iodine-131 enters the thyroid tissue and emits β-rays (99%) and γ-rays (1%), and the effective range of β-rays is only 0.5~2mm, which can selectively destroy the thyroid follicular epithelium without affecting the neighboring tissues, and even less radiation impact on the surrounding population. Since the world first used iodine-131 to treat hyperthyroidism in 1942, so far 1 million cases have been treated abroad and 100,000 cases have been treated in China. According to a special survey, the incidence of thyroid cancer and leukemia after iodine-131 treatment of hyperthyroidism is not significantly different from that of the general population. Iodine-131 treatment of hyperthyroidism is a popular treatment method because of its precise efficacy, high cure rate, safety, reliability, simplicity and ease of implementation. It should be mentioned that radioactive iodine-131 cannot be bought in general pharmacies, and the treatment can only be carried out in the nuclear medicine department of hospitals. Of course, hyperthyroidism patients should go to regular hospitals no matter which treatment method they take, so as not to miss the treatment.