The first two are T3 and T4, the second is TSH, the first two are mainly thyroid hormones and the third is thyroid stimulating hormone. If all three are in the normal range, the thyroid gland is functioning normally. If one of the first two is elevated and the third is decreased, the thyroid is in a hyperactive state. If one of the first two items is elevated and the third is elevated, thyroid function is hypothyroid and should be treated accordingly depending on whether the thyroid is hyperthyroid or hypothyroid. If the third item is elevated or decreased, it is a subclinical condition and no intervention is needed for the time being. External intervention will be performed only after the decrease reaches a certain standard value, and the clinician needs to develop a reasonable treatment plan according to the index.