Ms. Zhang, 35 years old, was afraid of heat, excessive sweating, and panic for more than three years, accompanied by irritability, insomnia, and hand trembling. She was diagnosed as “hyperthyroidism” in a large local hospital, and her symptoms were relieved by long-term oral medication. However, the previous symptoms worsened with every exertion, mood swings and cold. This female patient was very distressed, why some hyperthyroidism patients were cured after three years of medication, but she could not be cured. She was introduced to Wuhan First Hospital by a patient. After a detailed inquiry, the specialist suggested that the patient should have an antibody and ultrasound examination to clarify the cause of the disease. The results showed that the antibody titer was significantly higher, consistent with chronic lymphocytic thyroiditis, and the diagnosis of chronic lymphocytic thyroiditis was confirmed by a fine needle aspiration of the thyroid gland. The answer to this question is yes. The answer is yes, hyperthyroidism is only a clinical symptom, but there are many causes that can lead to hyperthyroidism, and only when the cause is clearly identified can the treatment be targeted. The treatment of hyperthyroidism is also very individualized. Let’s look at the causes of hyperthyroidism: diffuse toxic thyroid disease, multinodular toxic goiter, autonomic hyperfunctioning thyroid adenoma, follicular thyroid cancer, iodine-induced hyperthyroidism, pituitary TSH tumor or hyperplasia-induced hyperthyroidism, thyroiditis (subacute granulomatous thyroiditis, subacute lymphocytic thyroiditis, chronic lymphocytic thyroiditis, postpartum thyroiditis), exogenous thyroid hormone replacement, and ectopic thyroid hormone production. Indeed, there are many causes of hyperthyroidism, so how can we better understand it? The first step is of course to identify the cause of hyperthyroidism. Only when the cause is clearly identified can we choose a targeted treatment plan, and a clear cause has important implications for treatment and prognosis. There are three main tools for treating hyperthyroidism: surgery, isotope therapy and medication. Depending on the condition, they can be used alone or in combination. In case of thyrotoxicosis caused by excessive production of thyroid hormones by the thyroid gland itself, such as diffuse toxic thyroid disease and Hashimoto’s thyrotoxicosis, drug therapy is preferred. In case of exogenous or ectopic hormone secretion, pregnancy-related diseases, diet-induced hyperthyroidism such as iodine-induced hyperthyroidism, HCG-related hyperthyroidism, pituitary TSH tumor or hyperplasia-induced hyperthyroidism, exogenous thyroid hormone replacement, and ectopic thyroid hormone production, the treatment of the primary cause should be the fundamental. Since the cause of hyperthyroidism is so important, how can its cause be identified? The main tests for thyroid include: thyroid hormone measurement, thyroid autoantibody measurement, thyroid imaging and thyroid fine needle aspiration cytology. The first thing you should know is whether you have hyperthyroidism. A thyroid function test (FT3+FT4+TSH) will help you to find out. If you have already found out that you have hyperthyroidism, it is especially important to have a clear cause at this time. So how do we clarify the cause? I131 uptake is increased in thyrotoxicosis due to hyperthyroidism (including diffuse toxic thyroid disease, Hashimoto’s thyrotoxicosis, autonomously hyperfunctioning adenoma of the thyroid, and multinodular toxic goiter) and decreased in thyroiditis (including subacute granulomatous thyroiditis, subacute lymphocytic thyroiditis, chronic lymphocytic thyroiditis, and postpartum thyroiditis). Subacute granulomatous thyroiditis: history of infection, pressure pain in the thyroid, ESR >100 mm/H; chronic lymphocytic thyroiditis: significant increase in TPOAb and TgAb titers, uneven distribution of ECT nuclei, visible nodules, lymphocytic infiltrate seen in thyroid fine needle aspiration cytology; postpartum thyroiditis: mostly develops within one year after delivery, TPOAb (+), TRAb (-); diffuse thyroiditis. TRAb (-); diffuse toxic thyroid disease: TRAb (+), TSAb (+), enhanced homogeneous distribution of nuclei on thyroid radionuclide scan (ECT); multinodular toxic goiter: uneven distribution of nuclei on ECT, focal distribution of enhanced and attenuated areas; autonomously high-functioning thyroid adenoma: enhanced nuclei on ECT in the tumor area, sparse distribution of nuclei in other areas. Other factors such as iodine-induced hyperthyroidism, HCG-associated hyperthyroidism, pituitary TSH tumor or hyperplasia-induced hyperthyroidism, exogenous thyroid hormone replacement, and ectopic thyroid hormone production are associated with hyperthyroidism. Hormone production, etc. can be identified with a history of pregnancy, medication, diet, and relevant tests such as HCG and pituitary MRI. Although there are various causes of hyperthyroidism, there is no need to worry. With the continuous progress of science and technology, our means and techniques of diagnosis and treatment have been improved. If you suspect that you are suffering from a related disease, you must first go to a regular medical institution, consult a specialist and improve the relevant tests to clarify the cause. Only when the cause is clear, you can take less detours and strike quickly to achieve the best treatment effect, not just headaches and foot pains. It is also important to keep your mood relaxed, combine work and rest, get up and down on time, and eat regularly, which are also very important for your condition to improve. Finally, I would like to wish you all a speedy recovery!