Deep vein thrombophlebitis -Phlebography of the left calf in front view. Thrombophlebitis is an inflammation of the veins associated to a thrombosis (that is generally the cause). Deep vein thrombosis is the formation of thrombus at the level of the leg deep veins (here, tibial veins).It is more frequent among persons who remain sitted long hours (at work). It is also the pathology of the economy class syndrome (or jet leg), occuring to persons taking frequent long-haul flights. The move of the thrombus into the blood circulation can lead to a pulmonary embolism. The deep vein thrombosis and its consequences, the pulmonary embolism, are brought together under the term thromboembolic disease.