Deep vein thrombosis (DVT), which usually occurs in the lower extremities, is the presence of a blood clot within a deep vein that causes symptoms by breaking the venous return. Many cases of calf vein DVT are asymptomatic, or display only mild symptoms. But in the case of a proximal DVT, it affects the venous flow through the entire lower extremity, which results in a post-thrombotic syndrome, or a pulmonary embolism, if the proper treatment isn't performed. The diagnosis of the DVT is made by a radiologic examination. An ultrasound is often used as a first line of diagnosis, but on the other hand, computed tomography venography has also been gaining traction as an alternative method. If diagnosed, finding the cause of the DVT is important, and in the case of a symptomatic proximal DVT, the combination of anticoagulation and interventional treatment can be used towards the recovery of the venous return, preventing complications.