Thyroglobulin is a five-item thyroid function test. The test items are thyroid stimulating hormone (TSH), free triiodothyronine (FT₃), triiodothyronine (T₃), free thyroxine (FT4) and thyroxine (T4). The above five indicators can determine whether the thyroid function is abnormal or not, which is an important reference for the diagnosis of hypothyroidism, hyperthyroidism and other diseases. 1. Thyroid Stimulating Hormone: TSH is a diagnostic indicator that can reflect primary and secondary hypothyroidism. The reference range is 0.35~5.5μ IU/ml. 2. Free triiodothyronine: The reference range is between 3.5~6.5 pmol/L. It is a hormone synthesized and secreted by thyroid follicular cells. 3. Triiodothyronine: the reference range is 0.6-1.81 ng/ml, which is formed by deiodination of thyroxine in the liver and kidney. 4. Free thyroxine: the reference range is 11.5-22.7 pmol/L, which is a sensitive indicator of thyroid function. 5. Thyroid hormone: the reference range is 66-181 nmol/L, which is synthesized and secreted by the follicular epithelial cells of the thyroid gland. It should be noted that the 5-item thyroid function test is usually performed on an empty stomach. If the result is abnormal, it is recommended to consult a doctor in time for diagnosis and treatment under the guidance of a doctor.