Danger! Deep Vein Thrombosis
Could you have a life-threatening blood clot?
Deep Vein Thrombosis: An Unrecognized Danger continued...
"There's no question that DVT is underreported," says Samuel Z. Goldhaber,
MD, a professor of medicine at Harvard Medical School and cardiologist at
Brigham and Women's Hospital in Boston. "For every one case that we know about,
there are probably five that we don't."
The tragedy is that most of those deaths could have been avoided with simple
precautions or treatment. According to the American Public Health Association,
deaths from deep vein thrombosis may be the most common preventable cause of
But not enough people -- or doctors -- are truly aware of the risks.
What Is Deep Vein Thrombosis?
DVT is caused by a blood clot -- or thrombus -- that develops in one of the
larger veins in your body, usually in the lower legs. Occasionally, it can
develop elsewhere, like in the arms, says Merli. The clot can partially or
completely block the circulation in the area around it.
Deep vein thrombosis can cause problems in itself. But its greatest risk is
that part of the blood clot will break away and travel through the
The veins carry the clot up the legs, to the heart, and into the lungs. If
the clot lodges in one of the arteries of the lungs, it can prevent oxygen from
getting into the blood. This is called a pulmonary embolism. It can be treated
in many cases. But if the clot completely blocks the artery, as it did in David
Bloom's case, it can cause death.
Who Is at Risk for Deep Vein Thrombosis?
Blood clots can develop for various reasons. They most often occur if your
circulation is decreased or slows down in a particular area. When blood stops
flowing freely, it becomes stagnant and naturally begins to clot.
"There are three classic factors in developing DVT," says Bruce A. Perler,
MD, chief of the division of vascular surgery at Johns Hopkins School of
Medicine in Baltimore. They are:
Prolonged immobility. If you're in a confined area for
long periods of time and can't stretch your legs, your circulation can get
worse. This is why deep vein thrombosis is more common in people who are stuck
in bed or taking long trips. Because DVT often occurs after long plane flights,
it is sometimes called "economy class syndrome."
Trauma -- from an accident or surgery. Damage to the
tissue can increase the blood's tendency to clot. This can happen after
accidents or, more often, after an operation.
Genetic predisposition to clotting. Some people --
although many of them don't know it -- have inherited a higher risk of getting
deep vein thrombosis. Their blood is more likely to clot than average. After
his death, doctors discovered that Bloom had a genetic blood disorder.