Hypothyroidism is a group of diseases characterized by hypothyroidism. The causes of different types of hypothyroidism vary and the prognosis is not the same. For some secondary hypothyroidism, it is possible to recover if the primary cause is removed. For example, if the hypothyroidism is caused by drugs or physical or chemical factors, it is possible to cure it completely by stopping the drugs that affect the thyroid gland, keeping away from the curative factors, and supplementing with medication. However, hypothyroidism caused by some autoimmune factors is often difficult to cure and requires lifelong medication. The symptoms of different types of hypothyroidism are similar, and auxiliary tests are needed to distinguish them. 2. Thyroid function tests: T3 and T4 are reduced and TSH level is increased in primary hypothyroidism. In subclinical hypothyroidism, only TSH is elevated, T4 and FT4 are normal. 3.Thyroglobulin antibody (TgAb) and peroxidase antibody (TPOAb) are important indicators to determine the cause of primary hypothyroidism, and thyroid autoantibodies are significantly elevated in Hashimoto’s thyroiditis. 4. TRH excitation test: It is meaningful to distinguish primary hypothyroidism from pituitary hypothyroidism. In primary hypothyroidism, TSH is further elevated after TRH excitation, while in pituitary hypothyroidism, TSH response is low. Therefore, whether hypothyroidism can be cured cannot be generalized, the prognosis of different types of hypothyroidism is different, and the conclusion can be drawn only after the type is determined by examination.