Usually, we will refer to hyperthyroidism as “hyperthyroidism” for short, which is mainly manifested by an absolute increase in the value of thyroid hormones and some clinical symptoms brought about by it. As the thyroid gland synthesizes and releases too much thyroid hormone, it causes hyper metabolism and sympathetic excitation, resulting in hyperphagia, polyphagia, increased bowel movements, hypokalemia, palpitations, sweating, weight loss and other symptoms, and many patients also have accompanying problems such as protruding eyes, edema, and loss of eyesight. However, hyperthyroidism itself is not a specific diagnosis, not as a stand-alone disease, because we are talking about hyperthyroidism is just a symptom that can be caused by many diseases, in the grassroots hospitals or folk, often overlooked the problem, found that the thyroid hormone is elevated on the rush to treat, and do not go to actively look for the specific causes. Common causes of hyperthyroidism include diffuse toxic goiter (also known as Graves’ disease), subacute thyroiditis, painless thyroiditis, postpartum thyroiditis and Hashimoto’s thyroiditis, hypersecretory tumors of the thyroid gland, drug-induced hyperthyroidism, HCG-associated hyperthyroidism, hyperthyroidism in pituitary TSH tumors and hyperthyroidism in ectopic TSH tumors, as well as the rare thalamic hyperthyroidism and genetic variant hyperthyroidism. etc. There is also a proportion of hyperthyroidism for which no specific cause can be found. The vast majority of hyperthyroidism is usually caused by Graves’ disease, which accounts for about 80% or more of cases. Also known as toxic diffuse goiter, it is an autoimmune disease that does not manifest itself only in the thyroid gland, but is a multisystemic syndrome that also includes hypermetabolic syndrome, diffuse goiter, ocular signs, skin lesions, and thyroid telangiectasia. Other causes should not be ignored and should be recognized in a timely manner, as the treatment is different for different causes and not just antithyroid therapy. Of course, the diagnosis of hyperthyroidism is not difficult and can be made by considering hyperthyroidism and performing thyroid function tests. In hyperthyroidism, the thyroid gland secretes significantly higher T3, T4, FT3, and FT4, and TSH is often lowered due to feedback from the thyroid and pituitary axes. If a patient has elevated T3, T4, FT3, and FT4 accompanied by a decrease in TSH, he or she is hyperthyroid. Since the majority of hyperthyroidism is Graves’ disease and some is the hyperthyroid phase of Hashimoto’s thyroiditis, both of which are thyroid autoimmune disorders, it is often accompanied by elevated thyroid autoantibodies, thyroglobulin antibodies and thyroid peroxidase antibodies. In Graves’ disease, the thyrotropin (TSH) receptor antibody TRAb is clinically positive due to the production of TSI, an immunoglobulin that stimulates thyroid function in the filter cells. Other patients with hyperthyroidism may have elevated T3 and FT3, normal T4 and FT4, and decreased TSH, which we call “T3 hyperthyroidism”. “T3 hyperthyroidism” is often seen in elderly patients with hyperthyroidism or toxicity of the function of autonomic thermal nodules. In addition, some hyperthyroidism has elevated T3 and FT3, and T4 and FT4 are also elevated, but TSH is in the normal range or elevated, there are three possibilities, one is the pituitary gland or extra-pituitary TSH tumor, or it may be the thyroid hormone resistance syndrome (SRTH), also known as thyroid hormone dysregulation syndrome or the thyroid hormone insensitivity syndrome, or it may be thyrotropin-releasing hormone production of hypothalamus is significantly increased. hormone-releasing hormone production in the hypothalamus is significantly increased. Please do not just test T3, T4, and TSH for a first-time thyroid patient, as this is not enough. Please note that the first examination should check the complete set of thyroid function and all related antibodies, and pay attention to the thyroid image changes, and pay special attention to the accompanying symptoms and extra-thyroid symptoms, and do regular review in time. Therefore, primary care doctors must realize that hyperthyroidism is nothing more than a symptom, and once detected, they should get to the bottom of the problem and thoroughly explore the cause of the disease. If the primary care doctor is unable to complete the diagnostic process, he/she should transfer to a higher level hospital for confirmation of the diagnosis in a timely manner, and should not rush into blind drug treatment.