Danger! Deep Vein Thrombosis

David Bloom -- an NBC news correspondent -- called his wife from a few miles outside Baghdad, resting on the fender of a tank. It was April 2003, and Bloom had spent several weeks traveling in military vehicles across the deserts of Iraq.

He casually mentioned that he was having leg cramps, but neither he nor his wife, Melanie Bloom, thought much about it. "Cramps didn't seem unusual, since he was sleeping most nights inside a tank with his knees up to his chin. Everyone was having aches and pains," she tells WebMD. Besides, Bloom -- who was 39 -- had always been in excellent health.

What they didn't know is that Bloom had developed deep vein thrombosis (DVT), a blood clot in the leg -- partly the result of dehydration and traveling in cramped conditions. A few days later, as troops prepared a final push across the Baghdad border, David Bloom collapsed and died. The clot had traveled through his bloodstream to his lungs and killed him.

Melanie Bloom had many fears about her husband being in Iraq. DVT was not one of them.

"He did everything he could to stay safe," she recalls. He wore a chemical suit, and at times a flak jacket and a gas mask. "But the irony is that despite all those precautions, it was something inside his own body that took his life."

Deep Vein Thrombosis: An Unrecognized Danger

Like most people in the U.S., Bloom knew nothing about the condition. "Prior to the midnight phone call when I found out that David had passed away," Bloom says, "I had never, ever heard of DVT."

A 2002 survey conducted by the American Public Health Association found that 74% of U.S. adults knew little or nothing about it. But everyone needs to be aware. Tragically, David Bloom's story is not unusual. Every year, 2 million people get deep vein thrombosis and up to 200,000 of them die.

"DVT kills more people every year than AIDS, breast cancer, and motor vehicle accidents combined," says Geno J. Merli, MD, director of internal medicine at Jefferson Medical College in Philadelphia. "Most patients, and even many physicians, don't realize that."

"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 hospital death.

But not enough people -- or doctors -- are truly aware of the risks.