Deep vein thrombosis is a medical term that is used to describe the development of a blood clot in the deep veins of the legs. These clots are most likely to occur in individuals who are inactive for long periods, such as office workers or airline passengers who cannot move about freely.

One of the major causes of deep vein thrombosis (DVT) (also know as a deep vein blood clot) is long periods of inactivity. When the leg muscles are not used for long periods of time and remain stationary, blood flow back to the heart begins to decrease. When this occurs the risk of blood clotting within a vein significantly increases.