Deep vein thrombosis--risks and diagnosis.

Background: Venous thromboembolism, comprising deep vein thrombosis (DVT) and pulmonary embolism, is common in Australia and is associated with high morbidity.

Objective: This article provides a summary of the risk factors for DVT of the lower limb and discusses the diagnosis of the condition using a diagnostic algorithm incorporating clinical assessment, D-dimer testing and imaging studies. It also briefly reviews the clinical significance of isolated distal lower limb DVT and superficial vein thrombosis.

Discussion: Many conditions in the lower limb mimic DVT. Diagnosing DVT on clinical grounds without objective testing is unreliable. Patients incorrectly diagnosed as having DVT may be subjected to unnecessary anticoagulation and its associated risks of bleeding. In contrast, there is a risk of thrombus extension and embolisation when DVT is missed or inappropriately treated.