The clinical diagnosis of acute deep vein thrombosis (DVT) is traditionally regarded as inaccurate and unreliable. In part, this is because the signs and symptoms of acute DVT are confused with the inflammation from infection, pain, and swelling of soft tissue injury, and nonvenous causes of edema. Furthermore, nonocclusive clot may remain asymptomatic until it embolizes, causing signs and symptoms of a pulmonary embolism (PE), or the vein becomes occluded. Therefore, nonocclusive thrombus that does not disturb venous return and which is not associated with inflammation of the vein wall remains asymptomatic. This becomes particularly troublesome when large veins become involved, particularly nonaxial veins such as the hypogastric veins, since pulmonary emboli can occur before leg symptoms, and these emboli can adversely affect cardiopulmonary hemodynamics and potentially result in fatality because of their large size. However, clinical presentation and physical findings can be helpful in patient evaluation.