What is venous thromboembolism?
A venous thromboembolism is a blood clot that blocks the flow of blood. "Thrombo" means blood clot, and "embolism," means a circulating particle that causes an obstruction. "Venous" means in the veins. When healthcare providers talk about venous thromboembolism (VTE), they often talk about it as a disorder that can lead to two different kinds of blood clotting conditions: deep vein thrombosis and pulmonary embolism.
Veins carry blood from the extremities of your body back to your heart. When a vein is blocked, blood pools behind the blockage, causing inflammation, and cells ahead of the blockage can’t get the oxygen and nutrients they need. This can do serious damage to the veins, tissues and organs that they feed. In some cases — such as when a VTE blocks blood flow to the lungs — it can be life-threatening.
How does venous thromboembolism occur?
Blood clotting is a normal and healthy response to a superficial cut or wound. Your blood coagulates — partially solidifies — in order to keep it from leaking too fast from a hole. On the outside of your body, this produces a scab. On the inside of your body, it produces a clot. Blood clotting can also be triggered by an infection, which irritates the lining of the blood vessel like a wound. When the wound or infection begins to heal, the clot is supposed to dissolve. But sometimes it doesn’t. And sometimes blood clots form when there was no wound. Many factors can contribute to this. If the clot is big enough, it can block the vein.
Advertisem*nt
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy
How does venous thromboembolism affect my body?
A venous thromboembolism is not the type of blood clot that typically causes a heart attack or stroke. Those are usually caused by blood clots in your arteries, not in your veins. But a VTE can be just as dangerous. The most serious complications occur when a VTE breaks loose from where it formed, travels through your bloodstream, and gets stuck in the veins of your lungs. This is called a pulmonary embolism (PE). A PE restricts oxygen and blood flow to your lungs while increasing blood pressure in your arteries. This causes pulmonary hypertension, which in turn can cause heart failure and death.
VTEs usually form in the deeper veins of your body, embedded in the muscles of your legs or arms. When a blood clot is stuck in your deeper veins, it’s called a deep vein thrombosis (DVT). A DVT that blocks the vein causes inflammation at the site of the blockage and can cause long-term damage to the vein, resulting in chronic venous insufficiency (post-thrombotic syndrome). Not all DVTs cause an obstruction, but because they can, they are considered a venous thromboembolic disease. DVTs can also break loose and travel to your lungs, leading to pulmonary embolism (PE).
What is the difference between a thrombosis and a thromboembolism?
A thrombosis is a blood clot. A thromboembolism is a circulating blood clot that gets stuck and causes an obstruction. Both deep vein thrombosis and pulmonary embolism are included under the umbrella term of venous thromboembolic diseases because both have the potential to obstruct blood flow in your veins. Blood clots that occur in the smaller, superficial veins close to your skin (superficial venous thrombosis) don't tend to cause the same kinds of complications. About half of DVTs don’t cause complications either, but they can, and they remain a risk factor for PE.
Advertisem*nt
How common is VTE?
In the U.S., VTE is the third most common vascular diagnosis after heart attack and stroke. It affects about 1 in 1,000 Americans each year. About half of people with VTE experience a pulmonary embolism. About 25% of those who have a pulmonary embolism die from it. After the age of 40, your risk of VTE almost doubles every decade.
Who does venous thromboembolism affect?
Anyone can get a VTE, but certain factors put you more at risk. About 25% to 50% of cases arise without obvious cause. Another 20% are associated with cancer, and 20% with surgery. Some people also have blood clotting disorders that make them more prone to clots.
