γγT3, T4, FT3, TF4 and TSH are the thyroid hormones secreted by the thyroid gland, they can bind to the proteins in the blood serum, but to function, they must be separated from the proteins in the blood, so the measurement of free thyroxine FT3 and FT4 better reflects the function of the thyroid gland. If there is less thyroxine in the body, that is, when the thyroid gland is hypothyroid, TSH will rise and promote the thyroid gland to produce more thyroxine; on the contrary, in hyperthyroid patients, because there is already too much thyroxine in the body, TSH will be reduced. In patients with chronic inflammation of the thyroid gland, TPO-Ab and TG-Ab need to be checked because they reflect the patient’s inflammatory status. For patients suspected of hyperthyroidism, TR-Ab should also be checked. An abnormally high level may indicate primary hyperthyroidism.γγIn addition to the above 8 indicators, doctors sometimes prescribe calcitonin (CT), thyroglobulin (TG), parathyroid hormone (PTH) and other indicators for different patients, the significance of the specific indicators should be analyzed in the context of the condition.