Causes of Deep Vein Thrombosis
What is DVT? Also known as deep vein thrombosis, DVT is a condition involving blood clots in veins situated deep within legs. DVT affects between 2 and 3 million Americans every year. Among them, just 600,000 receive treatment.
What makes deep vein thrombosis especially dangerous? If untreated, a piece of a deep-vein blood clot can break loose and travel to the lungs, causing pulmonary embolism—a condition that claims approximately 60,000 Americans annually. DVT also can cause ulcers or varicose veins.
The condition causes leg pain, swelling and skin discoloration—or redness. Frequently, DVT signs show up in just one leg. For example, it is not uncommon for air travelers to notice one leg is swollen or painful after a long flight.
What is DVT Caused By?
Generally speaking, causes of deep vein thrombosis can be both genetic and behavioral. For example, having a family history of parents or siblings suffering from blood clots, or having blood that coagulates easily, can predispose you to DVT. An undiagnosed clotting disorder can put you at risk, as well. Behavior-related causes of deep vein thrombosis include smoking and obesity.
 |
|
The anatomy of a deep-vein blood clot: Clotting agents called
"platelets" (in turquoise) attract each other as they pass
through the bloodstream. Platelets build up and block red
blood cells from carrying nutrients to surrounding tissues. |
Other contributing causes of deep vein thrombosis include:
- Surgery or traumatic injury
- Cancers and their treatments, both of which may adversely affect the blood’s ability to clot
- Other serious illness such as congestive heart failure, heart attack, stroke or sepsis
- Varicose veins
- People who are pregnant, taking oral contraceptives or incurring other hormonal changes
- Third trimester pregnancy and immediately following delivery
- Contraceptives/estrogen therapy (This risk increases in smokers.)
Regarding "triggering events" for the condition, these specific causes of deep vein thrombosis typically revolve around extended sedentary behavior. When we’re healthy, our muscles help our blood keep moving. But when we’re not moving around, blood tends to pool and clot at the lowest part of the body. Blood pressure is relatively low in the veins that return blood to the heart.
Prolonged bed rest due to illness—and recovery from surgery or trauma—are common causes of deep vein thrombosis. Likewise, sitting on an airplane for six or more hours without moving around is one of the leading causes of deep vein thrombosis. For this reason, DVT is often referred to as "economy class syndrome."
People who have had injury to their veins—due to trauma, athletic accidents or surgery—also are at higher risk of DVT.