Deep vein thrombosis is a condition characterized by the formation of a blood clot in one or more of the dep veins of the body – usually within the legs. This condition can cause pain, leg swelling and changes in skin color or may not have any symptoms, and it can occur if you are sitting for a long time without moving your legs, as in a long car trip or on an airplane. A potentially life-threatening complication of deep vein thrombosis is a pulmonary embolism, which is what occurs when a blood clot formed in the leg or elsewhere migrates to the lungs. Potential symptoms of pulmonary embolism include a rapid heartbeat, dizziness, chest pain, shortness of breath and coughing up blood. Treatment for deep vein thrombosis includes blood-thinning and clot-busting medications, special blood filters and compression stockings.