A blood clot occurring in the subclavian vein, which leads to the brachiocephalic vein and the heart. Thrombi occur more commonly in the right side. Symptoms are primarily pain and edema of the upper extremity, neck, and face. Pulmonary emboli are a life-threatening complication of subclavian vein thrombosis. Many cases are associated with use of a central venous catheter. Other predisposing factors include hypercoagulable disorders and malignancy. Paget-von Schroetter syndrome is a rare cause of subclavian vein thrombosis. It presents in young, healthy patients after exercise. It is caused by a narrow thoracic outlet. Treatment typically consists of anticoagulation, extremity elevation, and local heat application.