Embedded with the 3rd Infantry Division, Bloom spent much of his time tucked inside an M-88 tank, his knees pulled to his chin. During one satellite phone call home, he casually complained to his wife, Melanie Bloom, about the pain in his legs.

Two days later, as troops prepared to roll into Baghdad, the 39-year-old reporter collapsed and died on the desert floor.

"The bitter irony is he didn't die from a bullet or IED explosion," said Melanie Bloom. "The bomb was buried deep within his own body."

David Bloom died from deep-vein thrombosis [DVT], a blood clot that usually forms in the deep veins of the legs. The clot can lead to a multitude of complications, the most serious of which is a pulmonary embolism.

When a piece of the clot dislodges, it can travel to the brain, lungs, heart or other areas, severely damaging organs. In David Bloom's case, it caused sudden death, said Robert Pendleton, director of University Health Care Thrombosis Services.

"This is an incredibly common but under-recognized problem," said Pendleton, who noted that pulmonary embolism occurs in about half of DVT patients.

Pulmonary embolisms kill about 300,000 people in the U.S. each year, more than those who die from AIDS and breast cancer combined. Pendleton said about 10 percent to 15 percent of all hospital-related deaths are caused by pulmonary embolisms; of those who die, 70 percent to 90 percent have no symptoms.

Melanie Bloom, who began working with the Coalition to Prevent Deep-Vein Thrombosis about four years ago, said her husband was at high risk for a pulmonary embolism.

David Bloom had traveled on long-haul flights between New York and Kuwait. Once on the ground, he suffered from dehydration. Bloom's autopsy also revealed that he had the Factor V Leiden mutation, genetically predisposing him to venous thrombosis conditions such as DVT.

"David's story has evolved," Melanie Bloom said. "It's a tragic tale and it's something else: It's a message and a means to help people everywhere recognize the risks and symptoms of DVT."

Risks for DVT include prolonged sitting, such as on a plane [commonly referred to as "economy class syndrome."] It also may be caused by recent surgeries, fractures, childbirth within the past six months, and the use of medications such as estrogen and birth control pills.

One of the best ways to prevent DVT, said Scott Stevens, director of the Venous Thromboembolism Program at Intermountain Medical Center, is to simply walk, or wear tight, elastic socks. The socks increase the pressure in the legs, he said, which in turn prevents stasis.

Stevens also encourages people to remind their doctors to give them anti-coagulation treatment during a hospital stay, which is when about 60 percent of DVT and pulmonary embolism cases occur.

lrosetta@sltrib.com