Hyperthyroidism is a common endocrine disease. It is a clinical syndrome in which excessive secretion of thyroid hormones causes increased excitability and hyper-metabolism in the nervous, circulatory and digestive systems of the body. Common symptoms include panic attacks, fear of heat, excessive sweating, hyperphagia, increased stools, menstrual disorders, irritability, lethargy, and weight loss. If the above symptoms and signs appear, it is likely that you are suffering from hyperthyroidism, and you should go to the hospital in time to have relevant examinations to make a clear diagnosis. The main tests related to hyperthyroidism are: thyroid hormone measurement (TT3, TT4, FT3, FT4, TSH); thyroid scan to understand the shape, location, size, nodules and function of the thyroid gland; thyroid ultrasound; and thyroid iodine uptake rate measurement. If elevated T3 and T4 levels (some people have only 1 elevation), decreased TSH levels and diffuse enlargement of the thyroid gland or toxic thyroid adenoma are found, the diagnosis of hyperthyroidism is basically confirmed. Su Patients suffering from hyperthyroidism do not need to panic, as this disease is completely curable with the development of medical science today. However, unlike a cold or flu, it will not be cured in a few days and there is a process. As long as you follow the doctor’s instructions and take regular medication, it is not difficult to cure. At present, there are four kinds of treatment methods in common use: internal anti-hyperthyroidism medication, surgery, radioactive iodine treatment and Chinese herbal medicine. Internal treatment refers to the use of anti-thyroid drugs, such as tabazol, hyperthyroidism, methylthioxypyrimethamine, propylthioxypyrimethamine, etc., which mainly play the role of inhibiting the synthesis of thyroid hormones. This is the commonly used method, and its advantages lie in the certainty of efficacy and simplicity of the method. The disadvantage of this method is that it has a long course of treatment, requiring at least two years of regular medication, and a high relapse rate of up to 50% after stopping medication. Surgery is also a treatment option for hyperthyroidism, especially for toxic thyroid adenomas. If the adenoma is removed cleanly, there is usually no recurrence of hyperthyroidism in the future. The disadvantage is that after all, it is a surgical procedure and carries certain risks, leaving scars on the neck after surgery, and a high recurrence rate (30%), especially in diffuse hyperthyroidism with enlargement of the thyroid gland. According to TCM theory, hyperthyroidism is considered to be caused by internal injuries and seven emotions, and the deficiency of yin and fire in the heart and liver, and dialectical treatment is also effective. The use of radioactive iodine treatment is currently recognized as an effective method in the world. Former U.S. President George W. Bush, who suffered from hyperthyroidism during his administration, was finally treated with radioactive therapy after consultation and discussion by many world-class medical experts. It is now included as the preferred method in many Western countries. Why can radionuclide iodine treat hyperthyroidism? This is because iodine is a necessary raw material for the synthesis of thyroid hormones in the thyroid gland. Radioactive iodine and stable iodine have the same physiological and biochemical properties, so the thyroid tissue also has a high absorption and concentration capacity for radioactive iodine. In general, the concentration of iodine in the thyroid gland can reach 25 times the plasma concentration. In patients with hyperthyroidism, the rate and amount of synthesized thyroid hormones increase, so the concentration of radioactive iodine is even higher, up to 90%. The effective half-life of iodine in the thyroid gland averages 3.5 to 4.5 days. Iodine-131 is an unstable radioactive radionuclide that emits γ and β rays during decay, with β rays accounting for 99% of the therapeutic effect. The large amount of concentrated radioactive iodine exposes the thyroid gland to radiation, and part of the thyroid tissue is destroyed, resulting in a decrease in thyroid hormone production and remission or cure of hyperthyroidism. Since the range of beta radiation is only about 1 mm, it can destroy the thyroid tissue but has little or no effect on the tissues and organs surrounding the thyroid. This shows that radioactive iodine is a safe and easy way to treat hyperthyroidism. Who is suitable for radioactive iodine treatment for hyperthyroidism? Iodine-131 therapy is generally considered appropriate for both male and female adult patients. In the early days of iodine-131 treatment for hyperthyroidism, there were concerns about the risk of cancer, leukemia, and congenital abnormalities in the fetus. After half a century of clinical practice, it has been proved that these concerns have been eliminated. According to the data of more than 1 million patients at home and abroad, no increase in the incidence of leukemia and thyroid malignancies has been found, fetal malformations do not exceed the natural incidence, and there is no effect on fertility and offspring development. These have been extensively reported in the literature. It is now unanimously accepted by experts that treatment with iodine-131 is contraindicated in patients with hyperthyroidism during pregnancy and lactation because it can cause hypothyroidism in the fetus or infant. Therefore, we believe that iodine-131 is a safe form of treatment for patients of all ages (including women of childbearing age and children), except for pregnant and lactating women, and that it should be the treatment of choice for adults. Treatment of hyperthyroidism with radioactive iodine is usually performed in the nuclear medicine department. The nuclear medicine doctor decides the time and dose of radioactive iodine based on a comprehensive analysis of the patient’s hyperthyroidism symptoms, clinical manifestations, laboratory test results, thyroid gland iodine absorption function and thyroid scan results. Generally speaking, after the diagnosis of hyperthyroidism is confirmed, some preparatory work should be done before treatment with iodine-131, such as controlling certain heavier complications and abstaining from iodine-containing foods or medications. Before and after taking iodine-131, some auxiliary therapeutic agents should be dispensed according to the clinical manifestations, and certain reactions should be noted some time after taking the drug. Most of the patients can be controlled after treatment, and a cure can be achieved with a single dose of the drug. A small number of patients require a second treatment. The effect of iodine-131 starts to appear more than 3 weeks after taking it, and within 3 months the symptoms gradually improve, the thyroid gland shrinks and some patients’ proptosis is reduced. 6-12 months the symptoms are completely eliminated. If a second treatment is needed, it should be done after six months, preferably 8 to 10 months apart. Some patients with hyperthyroidism have protruding eyes, which is called proptosis. The causes are complex and may be related to certain immune disorders in the body, and some people have found that there is a substance in the serum of these patients that is related to the occurrence of proptosis. The occurrence and aggravation of proptosis are not parallel to the condition of hyperthyroidism. Most patients with hyperthyroidism will not have their proptosis aggravated after iodine-131 treatment, but only a few cases may have their proptosis aggravated. This should be properly understood. Hyperthyroid patients generally do not have any reaction after taking iodine-131, and only a few patients experience some side effects. Some reactions that occur within 2 weeks after taking the drug are called early reactions, mainly nausea, vomiting, dizziness, weakness, and in a few patients, rash and itching, which are generally mild and can disappear on their own. Some patients may experience transient exacerbation of hyperthyroidism, which is usually temporary, and very few patients with severe symptoms have to be hospitalized for observation. The main complication in the late stage is hypothyroidism (also known as hypothyroidism). It is caused by insufficient synthesis and secretion or physiological effect of thyroid hormones. One type of hypothyroidism caused by iodine-131 treatment is transient hypothyroidism, which is mild and can disappear on its own after 6 to 9 months, because of the recovery of incomplete thyroid cells damaged by radiation or compensatory proliferation of residual tissues. The other type is permanent hypothyroidism, which is reported to occur in 2-5% of the first year, and increases by 2-3% each year as time goes on. After hypothyroidism occurs, normal thyroid function can be maintained as long as the appropriate amount of thyroxine is supplemented under the guidance of a doctor. Some scholars believe that hypothyroidism is a natural history of hyperthyroidism and can occur after various treatments, and is not unique to iodine-131 treatment. In summary, several methods of treating hyperthyroidism have their own characteristics, and it is necessary to develop the correct treatment plan for the individual patient. In contrast, radioactive iodine-131 treatment for hyperthyroidism is widely applicable, simple, safe and effective, with fewer doses, fewer complications, a high cure rate and low cost, and can be the first choice for most patients.