Abstract

‘I call him a perfect physician who judges it better to abstain from treatment than pursue one which might perturb the course of the malady’ (Maimonedes, 1125–1204). This might well apply to long-term anticoagulation, with the inevitable risk of bleeding, in a patient with deep venous thrombosis who is found to have factor V Leiden. There is no evidence that the risk of recurrence is any higher than in a comparable patient with no evidence of inherited thrombophilia.

INTRODUCTION

Advances in understanding the pathogenesis of thrombosis have led to a massive increase in laboratory investigations to identify causal factors in affected individuals. However, this approach to investigation, when employed indiscriminately, does not improve clinical management, may cause confusion, and is potentially wasteful of scarce resources. In this article I shall review the inherited and environmental factors contributing to thrombosis, and explore the clinical value of laboratory investigation for prothrombotic