弥漫性血管内凝血（diffuse intravascular coagulation，DIC）是以全身凝血因子瀑布的激活及广泛微血栓形成为特点的临床综合症，既可以表现为单纯的出凝血检验指标异常，也可以表现为严重出血，血栓形成及器官衰竭。DIC在重症患者中更为常见，往往和严重感染、感染性休克等情况合并存在，进一步恶化预后，增加病死率。DIC的诊断应该结合基础疾病、现病史、临床表现及实验室检查综合得出。凝血网络庞杂交错，凝血的启动往往伴随抗凝，纤溶及炎症系统的启动，并存在交叉反馈调节；目前的实验室检查仅能反映凝血网络中极小的一部分，不同病因可以存在同样的实验室检查结果，比如肝功能衰竭患者和DIC患者都可以表现为血小板减少及传统实验室凝血指标的变化。因此，临床判断（病史及体格检查）在DIC的诊断中尤为重要；实验室指标除帮助诊断DIC外，还可以帮助判断临床是否存在出血或血栓的倾向，及判断替代性治疗或抗凝治疗的反应性。DIC是一种综合症，不同的病因及不同的病程都可以导致DIC；目前，虽然存在多种DIC诊断标准，但临床上往往无法获得高度一致的诊断结果。DIC更缺乏规范统一的治疗方式或疗程，替代性治疗（输注血制品）和抗凝治疗均应根据患者出现的临床-实验室表型进行选择，力争获得最佳的风险效益比。

Diffuse intravascular coagulation(DIC) is a syndrome characterized by activation of coagulation cascades and systemic microthrombus formation. DIC can be presented as abnormal laboratory results of coagulation or severe hemorrhage, thrombosis, and organ dysfunction. DIC is one of the most common syndromes in critically ill patients and is always complicated by sepsis, septic shock, and significantly increased morbidity and mortality. The diagnosis of DIC should be based on medical history, underlying disease, clinical presentation and laboratory results. Given the complicated coagulation network, interaction and feedback regulation between coagulation, anticoagulation, fibrinolysis and inflammation are a tiny part of the whole coagulation network . Different etiology might present similar laboratory results, for example, thrombothytopenia and prolongation of PT. APTT could be found in patients with hepatic failure and DIC patients. Therefore, clincal judgement (history, symptoms and signs) should be valuable in the diagnosis of DIC. In addition to make a diagnosis, labobatory results also help to determine patients' tendency to hemorrhage or thrombosis, and to tell the effectiveness of either replacement transfusion or anticoagulative therapy. Although there are several diagnostic criteria, none satisfactory and highly agreed diagnosis has been achieved clinically. There is no consensus on treatment or treatment duration. Replacement transfusion or anticoagulative therapy should depend on patients' clinical-laboratory phenotype and on risk-benefit ratio.