Thyroiditis can be divided into acute, subacute and chronic thyroiditis. Of these, only acute thyroiditis is associated with bacterial infection, which is rare; subacute thyroiditis is associated with viral infection; and the most common is chronic lymphocytic thyroiditis, which is not related to infection but is an autoimmune disease. In addition, there is wood-like thyroiditis, also known as chronic fibrous thyroiditis, which is clinically rare. The first classification and characteristics 1, chronic lymphocytic thyroiditis, also known as Hashimoto’s thyroiditis, Hashimoto’s goiter or Hashimoto’s disease, is an autoimmune disease. A variety of antibodies can be detected in the blood, such as anti-thyroglobulin antibodies, anti-thyroid microsomal antibodies, anti-thyroid peroxidase antibodies and anti-thyroid cell surface antibodies. The clinical manifestation is a painless diffuse goiter, symmetrical, tough, or hard, with symptoms of pressure such as dyspnea and dysphagia in larger cases. 2. Subacute thyroiditis, associated with viral infection, is most often seen in 30-40 women. Most of them have a history of upper respiratory tract infection 1-2 weeks prior to the onset of the disease, which is characterized by sudden swelling, hardness and pain in the thyroid gland, and is often accompanied by pain in the ear and temporal region. Patients may have fever and increased blood sedimentation. The duration of the disease is about 3 months, and thyroid function does not decrease after healing. 3. Acute thyroiditis, also known as acute suppurative thyroiditis, is rare and is associated with bacterial or fungal infection. The onset of the disease is rapid, with high fever, thyroid masses, significant tenderness, local skin redness and fever. Second, the diagnosis is mainly based on clinical manifestations and laboratory tests. 1. Clinical manifestations: Most patients may present with enlarged thyroid gland, nodules, pain and pressure pain. In some patients, pain in the pharynx may be misdiagnosed as an upper respiratory tract infection. Laboratory tests: Some autoimmune antibodies are elevated, such as anti-thyroglobulin antibodies and anti-thyroid microsomal antibodies are significantly elevated. In patients with subacute thyroiditis, blood sedimentation is increased. Sometimes, the pain and enlargement of thyroid gland caused by thyroid cancer can be easily misdiagnosed as thyroiditis, which should be noted. The treatment 1. Except for acute thyroiditis, which requires antibiotics, all other thyroiditis do not require antibiotic treatment. The treatment of thyroiditis is mainly symptomatic for abnormalities in the size and function of the thyroid gland. (1) If the function of the thyroid gland is normal and there are no obvious symptoms of pressure, it can be followed and observed without treatment. (2) If the enlarged thyroid gland presses on adjacent organs or affects the appearance, thyroxine may be administered to reduce the size of the gland. (3) If hypothyroidism is present, take thyroxine treatment. Even in the case of transient hypothyroidism such as subthyroiditis, those who develop hypothyroid symptoms may be treated with temporary thyroxine replacement therapy. (4) If hyperthyroidism is present, it can be treated with antithyroid drugs, beta-blockers, etc. In general, hyperthyroidism caused by thyroiditis does not require surgery or 131 iodine treatment. (5) Glucocorticoids can make the enlarged gland smaller and reduce the symptoms, but they may relapse after stopping the medication, and there are certain potential adverse effects of hormones, so hormone therapy should be used with caution. (6) The thyroid gland of patients with thyroiditis is tough and hard, and sometimes it is difficult to distinguish it from thyroid cancer, so puncture or surgical pathology is needed. (7) During the observation or treatment of thyroiditis, thyroid function should be tested regularly to adjust the dose of medication. Patients should not self-medicate, change the dose of medication or stop medication.