血清 T_4升高多见于甲亢,但 T_4升高未必说明甲状腺功能异常。本文扼要介绍血清 TT_4升高而临床表现甲状腺功能状态正常的各种原因。提醒临床医师正确地估计甲状腺功能的实验检查.防止片面地单凭血清 T_4的升高而做出错误的诊断和导致不恰当的治疗。 Serum T_4 increased more common in hyperthyroidism, but elevated T_4 may not explain thyroid dysfunction. This article briefly describes the various causes of elevated thyroid serum levels and clinical manifestations of thyroid function. Remind clinicians to correctly evaluate the experimental tests of thyroid function, to prevent the one-sided diagnosis of incorrect diagnosis based on the rise of serum T 4 alone and to lead to improper treatment.