This is a must-have for thyroid specialists and necessary knowledge for thyroid patients. 1, the thyroid gland can have a variety of inflammatory conditions, a pathological state in which the thyroid gland is destroyed, the most common being chronic lymphocytic thyroiditis, also called Hashimoto’s disease, which is caused by the destruction of the thyroid gland by the body’s own toxic substances, namely autoantibodies, and can eventually lead to hypothyroidism. Hashimoto’s disease has a significant genetic predisposition and it is necessary to screen the patient’s next of kin. 2. Subacute thyroiditis is a type of thyroiditis between acute and chronic, characterized by pain in the thyroid area with lump formation, and can be moderately to highly febrile, evident in the late afternoon or evening. It is often preceded by a cold and can be easily misdiagnosed as pharyngitis or even a tumor, and requires special tests to confirm the diagnosis. Painless thyroiditis is an inflammation of the thyroid gland that is not uncommon but often not correctly diagnosed by doctors, and is often misdiagnosed as common hyperthyroidism and treated with anti-thyroid medication. When pregnant, the diagnosis requires a combination of thyrotropin receptor antibody TRAb and thyroid ultrasound due to limited testing. This condition can also be seen in the postpartum period, when it is called postpartum thyroiditis. Blood tests can show either hyperthyroidism or hypothyroidism. Painless thyroiditis is self-limiting and most people can recover naturally, but the hyperthyroid phase requires rest and symptomatic management. 4. Acute septic thyroiditis is a rare or uncommon inflammation of the thyroid gland, mainly in children, mostly due to abnormal thyroid development or other abnormalities of the neck, followed by bacterial infection, such as abnormal development of the cheek cleft. It may have an acute onset with high fever and blood work consistent with septic inflammatory changes, but nail function is generally normal. Local manifestations include a painful mass on palpation of one side of the thyroid gland, which has a congested and red skin appearance with intense pressure pain and high tension. The disease requires prompt antimicrobial and surgical management.