Diagnosis and management of heritable thrombophilias.

The term thrombophilia refers to an abnormality of blood coagulation that increases the risk of thrombosis. Such abnormalities represent one component of the triad (along with stasis and abnormalities of the vessel wall) put forward by Virchow in the 19th century to explain why thrombosis occurs. Thrombophilic abnormalities may be heritable (the topic of this review) or acquired, although both genetic and environmental factors influence activity within the coagulation system and may interact to provoke thrombotic events. Clinicians in primary and secondary care may need to counsel or manage asymptomatic people or patients with venous thromboembolism (VTE) who have either a family history of venous thrombosis or a known heritable thrombophilia. The purpose of this review is to help clinicians decide whether to test for a thrombophilic tendency, what tests to request if testing is to be done, and how to interpret and act on the results. What are the types of heritable thrombophilias?