Thyroiditis is a common thyroid disease, more common in women than in men, and is an autoimmune disease in which most patients contain antibodies against thyroid antigens in the serum and thyroid tissue. Thyroiditis is a heterogeneous disease of the thyroid gland caused by various causes. It is classified in order of incidence as chronic lymphocytic thyroiditis, subacute thyroiditis, painless thyroiditis, infectious thyroiditis and other causes of thyroiditis, with chronic lymphocytic thyroiditis and subacute thyroiditis being the most common. Chronic lymphocytic thyroiditis, also known as Hashimoto’s thyroiditis, is characterized by a diffuse enlargement of the thyroid gland, which may be uneven or accompanied by nodule formation. Some patients may show signs of hypothyroidism. Subacute thyroiditis is self-limiting and is the most common painful thyroid disorder, typically presenting with severe thyroid pain, which may be accompanied by fever, often with general malaise, malaise, and muscle pain, and eventually the thyroid gland usually returns to normal function. The clinical manifestations of thyroiditis are varied, and its causes vary, as do the clinical manifestations and prognostic differences. Thyroid function can be normal, or hyper or hypo, and sometimes all three functional abnormalities can occur, and some patients eventually develop permanent hypothyroidism, and sometimes different types of thyroiditis can transform into each other. Therefore, thyroiditis is a heterogeneous disease of the thyroid gland caused by various causes and can be clearly diagnosed by thyroid function tests, immunological tests, blood sedimentation, pathological tests, etc. Patients need to implement different treatments for different types of thyroiditis under the guidance of their doctors.