Deep vein thrombosis

### What you need to know Deep vein thrombosis (DVT) commonly affects the lower limb, with clot formation beginning in a deep calf vein and propagating proximally.1 It is a common venous thromboembolic (VTE) disorder with an incidence of nearly 1.6 per 1000 inhabitants a year.234 The rate of involvement of particular sites varies: distal veins 40%, popliteal 16%, femoral 20%, common femoral 20%, and iliac veins 4%.1 Certain medical conditions listed in box 1 increase the likelihood of clot formation in the deep veins. Upper limb DVT represents less than 10% of all DVT, and central venous catheters are the main risk factor.7 Venocaval thromboses are rare and are associated with malignancy, compression, and vascular abnormalities.8 This article provides an overview for non-specialists on initial approach to patients with suspected DVT. Box 1 ### DVT risk factors56 #### Transient risk factors #### Persistent risk factors #### Unprovoked VTERETURN TO TEXT ### Sources and selection criteria We searched Medline and Cochrane databases for clinical trials, systematic reviews, and meta-analyses relevant to the diagnosis and management of DVT. Search terms included “deep vein thrombosis,” …