© 2000 Canadian Medical Association or its licensors Commentary

An association between the risk of venous throm-boembolism and a hypercoagulable state has beenrecognized for some years. More recent advances in thrombosis research and laboratory medicine have pro-vided an ever-expanding list of specific laboratory anom-alies that may predispose people to venous thromboem-bolism. This article will review hypercoagulability with emphasis on laboratory risk markers and will provide some practical guidelines concerning the potential usefulness and limitations of such data in the context of patient manage-ment. An overview of procoagulant and anticoagulant reac-tions is shown in Fig. 1, and the conditions that promote a hypercoagulable state are summarized in Table 1. Hemostasis involves a concerted and complex series of reactions, integrating vascular, endothelial cell, platelet and plasma factor responses that regulate thrombus formation. In response to injury, or other prothrombotic stimuli, rapid changes in vascular endothelial cells will lead to both the release of intracellular proteins that participate in the he-mostatic process and an alteration of cell-surface proper-ties, promoting a thrombogenic environment. Platelet ad-hesion and activation and concurrent activation of the Risk factors for thromboembolism: pathophysiology and detectio