低T3综合征即正常甲状腺病态综合征，又称非甲状腺疾病综合征，广泛存在于临床各种重症疾病（如急性冠状动脉综合征、慢性阻塞性肺疾病、恶性实体瘤、急性胰腺炎、恶性血液肿瘤，肾功能不全、重症感染等）中。初诊患者血清中 T3和 T4水平变化与疾病的预后和发展关系密切。该文就低 T3综合征的发现历史、研究进展及其在危重症疾病中的预测意义及其替代治疗的可能作用进行综述。“,”Lower triiodothyronine(T3 ) syndrome is normal thyroidal syndrome,also named as nonthy-roidal illness syndrome,which exists in many severe diseases(including acute coronary syndrome,chronic obstructive pulmonary disease, malignant solid tumor, acute pancreatitis, malignant blood tumor, renal insufficiency,and severe infection,etc.).T3 and T4 levels may be good predictors for the development and prognosis of the diseases.Here is to make a review of the discovery history,research progress,and predic-tive value of low T3 syndrome,and the possible role of hormone replacement therapy.