Hashimoto’s disease, also known as chronic lymphocytic thyroiditis, is a group of endocrine disorders that slow down the systemic metabolic function due to necrosis of part or all of the thyroid follicles caused by lymphocytes in the thyroid gland with low immunity, resulting in a decrease in the thyroid gland’s ability to secrete thyroid hormones. Hashimoto’s disease should be alerted when the following symptoms occur: (1) When a diffuse swelling of the thyroid gland is present, the disease has been present for an average of 2 to 4 years. (2) Common symptoms are generalized weakness, many patients do not have throat discomfort, and 10% to 20% of patients have localized pressure or vague pain in the thyroid area, with occasional light pressure pain. (3) The thyroid gland is mostly bilaterally symmetrical and diffusely enlarged, with the isthmus and conus lobe often enlarged at the same time, or unilaterally enlarged. The thyroid gland tends to increase in size gradually as the disease progresses, but rarely compresses the neck and causes difficulty in breathing and swallowing. On palpation, the thyroid gland is firm, with a smooth or fine sandy surface, or nodules of varying size, usually without adhesions to surrounding tissues, and can move up and down during swallowing movements. (4) The cervical lymph nodes are usually not enlarged, but a few cases may also be accompanied by enlarged cervical lymph nodes, but the texture is soft. The diagnosis of Hashimoto’s disease is relatively easy to confirm, based on higher than normal values of anti-thyroid microsomal antibodies (TMAb) and anti-thyroglobulin antibodies (TGAb) and thyroid fine needle aspiration (FNAC), and a thyroid ultrasound showing chronic bilateral enlargement of the thyroid gland. Hashimoto’s disease is usually found in young women, making it difficult for women of childbearing age to conceive, while clinically, women of childbearing age have many biochemical pregnancies that are eventually found to be caused by the disease. Thyroid cancer: There are four types of thyroid cancer: papillary carcinoma, follicular carcinoma, medullary carcinoma and undifferentiated carcinoma. Different pathological types have different clinical manifestations. The first choice of treatment for thyroid cancer should be surgery. However, the extent of thyroidectomy for differentiated thyroid cancer has long been the focus of surgical debate because of the high recurrence rate (median 35%) after surgery. The treatment options are subtotal thyroidectomy and total thyroidectomy. The main postoperative complications include temporary hypoparathyroidism and permanent hoarseness and neck hematoma. Hashimoto’s and thyroid cancer: The incidence of Hashimoto’s disease combined with thyroid cancer, especially papillary thyroid cancer, has been on the rise in recent years. Hashimoto’s disease may be one of the high-risk factors for the development of thyroid cancer. There is no treatment for autoimmune thyroiditis that addresses the cause of the disease. Restriction of iodine intake may help to slow the progression of autoimmune destruction of the thyroid gland. Patients with pre-existing hypothyroidism or significant subclinical hypothyroidism must be treated with thyroid hormone replacement therapy. Principles of treatment for Hashimoto’s disease: 1. Drug therapy (1) If thyroid function is normal, no special treatment is needed, but follow-up is required, and ultrasound and thyroid function should be reviewed half-yearly. (2) Patients with hypothyroidism should undergo thyroid hormone replacement therapy, using thyroid tablets or levothyroxine until the maintenance dose is reached. The indicators for reaching the maintenance dose are improvement of clinical symptoms and normal TT3, FT3, TT4, FT4 and TSH. (3) Hashimoto’s disease will present with mild hyperthyroid symptoms in the early stage and most do not require treatment. It goes through four periods: hyperthyroidism, normal thyroid function, hypothyroidism and normal thyroid function. Transient hyperthyroidism can be treated symptomatically with beta-blockers. (4) Hormone therapy. This disease is generally not treated with hormones. For some patients with painful chronic thyroiditis, when the thyroid gland is painful and swollen, prednisone can be added. After improvement, gradually reduce the amount of medication for 1 to 2 months. (5) Selenium is an essential trace element in the human body and is an antioxidant. It has important physiological functions such as anti-aging, anti-tumor, cardiovascular protection and antagonism to heavy metal toxicity. Selenium can improve the immune function of human body. Selenium intervention therapy can reduce or inhibit the immune damage of autoimmune thyroiditis. In addition, we should develop good habits in life, reasonable diet, regular work and rest, and properly relieve mental stress. 2.Surgical treatment There are only two indications for surgery: (1) local compression symptoms affecting breathing; (2) concurrent thyroid cancer. In other cases, do not choose surgery easily. After surgery, most patients develop low thyroid function and need to take medication for life.