Thrombosis is the formation of a blood clot within a blood vessel causing a partial or total obstruction; it prevents blood from flowing normally through the circulatory system. An abnormally increased tendency toward blood clotting (caused by genetic, environmental, or unknown factors), endothelial cell injury of the vessel wall (exacerbated by infection or trauma), and static blood flow contribute to the formation of blood clots, according to the North American Thrombosis Forum.
Partial or complete detachment of the thrombus from the blood vessel wall allows the clot to embolize to vital organs such as the brain, heart, lungs, or leg arteries. The free-flowing blood clot lodges within the vasculature and obstructs blood flow. Life-threatening pathological conditions can occur as a result, such as stroke, heart attack, pulmonary embolism, or limb-threatening gangrene.
The precise number of people affected by DVT/PE is unknown, but estimates range from 300,000 to 600,000 (1 to 2 per 1,000, and in those over 80 years of age, as high as 1 in 100) each year in the United States, according to the Centers for Disease Control.
It is estimated that 60,000-100,000 Americans die of DVT/PE (also called venous thromboembolism)
Among those, people who have had a DVT, one-half will have long-term complications (post-thrombotic syndrome) such as swelling, pain, discoloration, and scaling in the affected limb and One-third (about 33%) of people with DVT/PE will have a recurrence within 10 years.
Venous thromboembolism (VTE) is a disease that includes both deep vein thrombosis (DVT) and pulmonary embolism (PE). Risk factors that contribute to VTE are varied and include: Immobilization; Hypercoagulability; Vessel wall damage; Age; Surgery (especially orthopedic surgery and total knee replacement); Cancer
Heredity (including the Factor V Leiden genetic mutation)
Increased estrogen levels (due to oral contraception or hormone replacement therapy)
Arterial thrombosis within the coronary arteries leads to myocardial infarction (heart attack), while obstruction of the cerebral vasculature causes stroke.
It is important to note that venous and arterial thromboses share many of the same risk factors, including cigarette smoking, hypertension, and diabetes mellitus.