This article reviews the incidence, causes, risk factors, diagnosis, treatment, complications, and prevention of deep vein thrombosis (DVT). Various employees, including long-distance drivers or travelers, sedentary office workers, females taking estrogen, those who are obese, those who have cancer, and those who are hospitalized, may be at risk for developing this condition. Genetic testing can determine some inherited factors predisposing workers to clotting. Low-molecular weight heparins can be used to manage DVT on an outpatient basis.