甲状腺机能亢进症(简称甲亢),是由于血液循环中甲状腺素及三碘甲状腺原氨酸异常增高,临床上出现一系列高代谢症群。近年来通过放射免疫法直接测定血清中甲状腺素浓度,提高了甲亢诊断率,但因血清中TT_3,TT_4浓度受血清中与甲状腺素结合球蛋白(TBG)的量和结合力的影响,所以血清TT_3,TT_4放免测定有时正常或偏低,影响了甲亢的诊断。本文通过两个病例对TT_3,TT_4正常 Hyperthyroidism (referred to as hyperthyroidism), is due to abnormal thyroid hormone and triiodothyronine in the blood circulation, clinically a series of high metabolic syndrome. In recent years, the serum thyroxine concentration has been directly measured by radioimmunoassay and the diagnosis rate of hyperthyroidism has been increased. However, serum concentrations of TT_3 and TT_4 are affected by the amount and binding of thyroxine binding globulin (TBG) in serum. TT_3, TT_4 radioimmunoassay sometimes normal or low, affecting the diagnosis of hyperthyroidism. This article through the two cases of TT_3, TT_4 normal