T4 in medicine is equivalent to FT4, currently the latter is not easily affected by the binding protein in the blood basically replaced the former, refers to a free thyroxine indicator that is not affected by the binding protein of thyroid hormone, which can directly reflect the functional state of the thyroid gland, its specificity and sensitivity is higher than the T3, usually in the lack of estrogen treatment during pregnancy, thyroid stimulating hormone test is particularly important. T4 is the main indicator of thyroxine human serum reflecting the function of the thyroid gland, with the growth of age serum concentration will slowly decrease. t4 abnormalities can choose medication, if after long-term drug treatment has no effect, you can also take surgical treatment or iodine radiation therapy, t4 abnormalities often mean that the thyroid gland is functioning abnormally, you need to go to the hospital in a timely manner with the relevant equipment checkups, and then according to the results of the examination to develop a reasonable and appropriate treatment program. It is necessary to go to the hospital in time and use the relevant equipment to check, and then according to the results of the examination to formulate a reasonable and suitable treatment plan, do not ignore it and let it develop, or it is easy to develop hypothyroidism or hyperthyroidism symptoms.