What is DVT?

Blood clotting protects us from severe blood loss after injury. A haemostatic balance is normally maintained, so that injuries from minor cuts to life-threatening wounds are repaired without excess blood loss. Quick, efficient return of blood to the heart using the power of the leg muscles is a crucial phase of the circulatory process. Our deep veins are surrounded by powerful muscles that contract to force blood back to the heart. One-way valves, inside the veins, prevent backflow of blood between muscle contractions.

When our circulation slows down due to inactivity, illness or injury, there is a tendency for blood to accumulate & form a pool. A static pool of blood provides an ideal environment for clot formation. When we are sleeping or inactive sitting upright, a pool can easily form in the lower legs.

DVT & PE (pulmonary embolism)

When DVT occurs a long, soft, blood clot forms usually attached at one end, often near a valve. The clot can become large and then break loose into the bloodstream. A clot may then be carried quickly by the movement of blood into the larger leg veins, and into the largest vein of the body. It will then go into the right side of the heart, then into the main branches of the arteries to the lung, so blocking the blood flow.
This is called pulmonary embolism (PE). If PE is severe it may cause a lung to collapse and heart failure.

PE is a common cause of sudden, unexpected death.

Summary from Nursing Center
Venous thrombosis involving the deep veins is a major US health problem that affects over 2.5 million people annually. The most serious complication of a deep venous thrombosis (DVT) is pulmonary embolism (PE), which is associated with 50,000 to 200,000 deaths each year.
www.nursingcenter.com/search/search.asp?R1=V1&query=dvt&searchAll=1