Every time I go out to the clinic, I meet patients with thyroiditis. Some of them ask if they can take anti-inflammatory drugs; others want to know what the thyroid gland is, why it is inflamed, what effects it has on the body, and whether it can be cured. Those who do not have thyroiditis would like to know what thyroiditis is, whether it can be prevented or how to prevent it, and so on. Now we will introduce the knowledge about goitre and hope to answer the questions of our friends. Thyroiditis is generally divided into three categories: acute, subacute and chronic. They have different causes, different clinical manifestations, and different treatment options. The most commonly seen clinical conditions are subacute thyroiditis and Hashimoto’s disease. Acute thyroiditis is caused by bacterial infection and manifests as interstitial thyroiditis or purulent inflammation, which is effectively treated with anti-inflammatory therapy and may be treated with puncture or incision and drainage when an abscess has formed. Acute thyroiditis is rarely seen clinically because the thyroid tissue is more resistant to bacterial infection. The most common type of thyroiditis is subacute thyroiditis, also known as granulomatous thyroiditis or giant cell thyroiditis, which occurs more frequently in women than in men around the age of 30. It is thought to be related to a viral infection. The duration of the disease varies from a few weeks to six months, usually two to three months, and is divided into three stages: early, middle and recovery. If treated promptly, most of the cases can be fully recovered, and only a very few cases will remain permanent hypothyroidism. The disease has a certain rate of recurrence. Typical cases have a rapid onset, with symptoms of upper whistle infection such as sore throat, chills and fever, followed by anterior neck pain. The pain may start on one side and gradually involve all of the thyroid gland, radiating to the jaw, gums, behind the ear, occiput, chest and back, and worsening when chewing, swallowing, eating, coughing, turning the neck or lowering the head. Enlarged and hardened, thickened thyroid glands with painful nodules can be felt on the surface and sides of the trachea in the anterior part of the neck. At this stage of the disease, due to destruction of thyroid follicles and increased release of thyroxine, hyperthyroidism such as palpitations, aversion to heat, excessive sweating, excessive food and hunger, increased frequency of stools, hand tremors, and irritability may appear. In the middle stage, due to severe destruction or fibrosis of the thyroid gland, hypothyroidism often appears, manifesting as fatigue, drowsiness, fear of cold and warmth, loss of appetite, abdominal distension, constipation, and swelling. Due to individual differences and other reasons, in some milder cases or cases with atypical presentation, the pain may not be obvious and the pressure pain may be mild, there may be no symptoms of viral infection such as fever, and symptoms of hyperthyroidism or hypothyroidism may not be present. In the recovery period, symptoms gradually decrease or improve, the enlarged thyroid gland gradually becomes smaller and softer or returns to normal, and the nodules may disappear or be slowly absorbed after the disease is cured. Early blood tests may show increased sedimentation, decreased white blood cells (which may also be normal), increased T3 and T4, decreased TSH, and increased thyroid immunoglobulin (which returns to normal later than thyroid hormones). The iodine uptake rate of the thyroid gland may decrease to less than 5%-10%, and the thyroid gland may be unremarkable or faint on nuclear scan. Ultrasound examination shows hypodense lesions at the site of pressure pain. Adrenal glucocorticosteroids have been shown to be effective in “subxiphoid” thyroiditis, with fever and pain resolving within 1-2 days and the thyroid gland shrinking significantly after a week. When using prednisone, thyroid tablets, anti-inflammatory and analgesic agents, and antiviral agents can be added as appropriate. The starting dosage of prednisone is 10 mg each time, 3-4 times a day. When the pain disappears and the thyroid gland shrinks (about 3-4 weeks), the daily dosage can be reduced by 5-10mg per week, and the maintenance dosage is 5mg per day for a full course of 2-3 months. In case of recurrence after discontinuation of the drug, prednisone treatment may be repeated. The daily dosage of levothyroxine tablets is about 50ug. Chronic thyroiditis includes: chronic lymphocytic thyroiditis and fibrotic thyroiditis. Chronic lymphocytic thyroiditis, also known as Hashimoto’s disease, is an autoimmune disease. It is characterized by enlargement of the thyroid gland and hypothyroidism. If the thyroid gland is obviously enlarged or has symptoms of pressure, short-term corticosteroid treatment is available. Only in a few advanced cases where the above treatment is ineffective, and when anterior cervical compression is evident, isthmus resection of the thyroid gland may be considered. Fibrous thyroiditis, also known as Riedel’s goiter, is very rare and its cause is unknown. It occurs mainly in middle-aged women. The lesions tend to start on one side. The thyroid gland is hard and nodular, with significant adhesions to the surrounding tissue, and is often associated with hypothyroidism. In advanced cases with symptoms of compression, the isthmus of the thyroid gland can be removed or a partial thyroidectomy can be performed, and thyroid preparations are given after surgery.