Hashimoto's thyroiditis, also known as chronic lymphocytic thyroiditis, is a common type of autoimmune thyroid disease. Hashimoto's thyroiditis is the most common cause of hypothyroidism. If hypothyroidism caused by Hashimoto's thyroiditis is identified, long-term administration of levothyroxine can achieve good control. It is worth noting that the clinical manifestations of Hashimoto's thyroiditis are often atypical, or may coexist with other thyroid diseases, or other autoimmune diseases. Special attention needs to be paid to certain types of Hashimoto's thyroiditis. One such type is Hashitoxicosis, Hashimoto's pseudohyperthyroidism, or Hashimoto's thyroiditis accompanied by thyroid tumors, Hashimoto's encephalopathy, or Hashimoto's with proptosis. These special types require particular attention.