-Activity restriction in the confined seated position results in diminished flow of venous blood from the legs back to the heart. This combined with pre-existing risk factors may lead to a more serious danger - travel-related thrombus. You may have heard this reported in the media as economy class syndrome (ECS). A travel-related thrombus is a venous thrombosis (blood clot in a vein) caused by traveling in a seated position for a long time. The venous thrombosis may be limited to a deep vein (DVT) or a fragment could flow to the lungs and lodge causing a pulmonary embolism (PE).
