American Society of Hematology guidelines issued for VTE. Among the recommendations: Blood-thinning drugs are preferred over mechanical prophylaxis for inpatients at high venous thromboembolism (VTE) risk. When medication is used to prevent VTE in inpatients, low-molecular-weight heparin is better than unfractionated heparin. Air travelers with no risk of thrombosis do not need to wear compression socks or take a blood thinner, such as aspirin. For diagnosis, use a D-dimer test in patients at low risk; if negative, no further tests are needed. Patients on warfarin do not need a short-acting injectable anticoagulant for invasive procedures. Low-molecular-weight heparin is the best therapy for superficial thrombosis in pregnant women. To read the guidelines, go to http://www.hematology.org/Clinicians/Guidelines-Quality/Guidelines.aspx.