While deep vein thrombosis (DVT) is not a well-known condition, popular ESPN reporter Bonnie Bernstein certainly knows about it. In 2006, DVT nearly killed her.

As the final whistle blew on the Oklahoma-Texas football game, Bernstein made a mad dash to her car a mile or so away from the stadium so she could make her flight home. As she sprinted to the car, her leg began aching and she had severe shortness of breath.

On the flight, Bernstein’s leg hurt more and started to swell. Thinking it was just a muscle spasm — and not connecting the shortness of breath with the leg pain — Bernstein went to see a chiropractor, who gave her stern instructions: “Go to an emergency department. Now! Get checked for blood clots.”

At Lenox Hill Hospital in Manhattan, emergency physicians found a massive clot in her left leg. Parts of the clot had broken off and had moved to her lungs. And that’s the real danger. When a part of a clot breaks off and goes to the lungs or the heart, it can cause a potentially lethal complication of DVT known as pulmonary embolism (PE).

“I was very lucky,” Bernstein says. Doctors treated her with blood thinners and released her from the hospital. But many people aren’t so fortunate.

“So many of us are still ignorant about DVT and its symptoms,” says Melanie Bloom. “The first time I heard of DVT was the night my husband died.” She’s talking about NBC television news correspondent David Bloom, who at age 39 — while traveling with troops in Iraq in 2003 — suddenly died from DVT. “The tragedy is that it is totally treatable,” says Bloom, who now serves as spokesperson for the Coalition to Prevent DVT, an advocacy organization that works to increase awareness.

While the precise number of people affected by DVT is unknown, the Centers for Disease Control and Prevention report that approximately 200,000 to 400,000 are affected each year, 100,000 to 200,000 of whom have PE. And nearly one-third of those with PE die.

According to polling by the coalition, 60 percent of Americans don’t know about DVT and its potentially lethal complications. Four years ago, the number was higher — 74 percent knew nothing about it. Lack of public awareness is what led the acting U.S. Surgeon General, Rear Admiral Steven K. Galson, MD, MPH, to announce a Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism, which aims to raise awareness about these conditions and reduce the number of DVT and PE cases.

The good news: awareness of DVT and PE — and how to treat them — is very high among emergency department personnel, says Dr. Francis Fesmire, an emergency physician in Chattanooga and a faculty member at the University of Tennessee College of Medicine.

As for patient awareness, the starting point, says Dr. Jeff Kline, a physician with the Carolinas Medical Center emergency department, is knowing these risk factors related to DVT:  

• Chronic illnesses such as heart disease or cancer
• Immobility (staying motionless in a hospital bed or an airplane seat)
• Surgery (especially of the hip, leg, knee, or abdomen)
• Age (risk increases with age)
• Using birth control pills or hormone replacement therapy
• Smoking
• Obesity

Having several of these risk factors can predispose an individual to clotting issues. In Bonnie Bernstein’s case, she spent many hours in airplanes as part of her job, she took birth control pills, and she learned from her mother — only after her close call — that she had the genetic risk factor, too.

If you have leg pain, cramping, or swelling, go to an emergency room to be checked for a blood clot, says Dr. Kline. “We diagnose one or two cases of DVT every week,” he says.

“If you have any symptoms of PE, get to the emergency room immediately,” cautions Dr. Fesmire. “PE is very serious and can cause death.” The symptoms of PE include:

• Difficulty breathing
• Faster than normal heartbeat 
• Chest pain or discomfort that can worsen with a deep breath or coughing coughing up blood 
• Lightheadedness

But Dr. Fesmire says, “The reality is that only about one-half of DVT cases have symptoms.” This is why knowing the risk factors — in particular, immobility — is so important.

That was what killed David Bloom, who, for many days and weeks leading up to his death, had been in cramped quarters inside a U.S. military M88 vehicle in the Iraq war zone. Although Bloom could not have simply opened the hatch and gotten out for a stretch, a simple way for most of us to help prevent DVT is to stay mobile, says Dr. Fesmire. On a lengthy airplane flight, for instance, get out of your seat and walk in the aisle for a few minutes every hour or so. When walking around isn’t possible, do foot and leg stretching exercises. Often that movement is enough to help prevent the clotting in deep veins.

Melanie Bloom recalls that just a few days before he died, her husband called her. “He was whispering” — he was in the war zone — “and he told me his leg was cramping up. He said it hurt, that he’d had this problem for a month. Two days later he was dead.”

If Bloom had seen a doctor when he started having symptoms, he’d have been quickly diagnosed and treated. Diagnosis of DVT typically involves an ultrasound test, a noninvasive procedure, and if DVT is caught early, it’s very treatable, says Dr. Kline. Initial treatment involves being put on a combination of oral and injected blood thinners, and may or may not involve hospitalization. In some instances, the patient will be advised to wear compression stockings. “Knee-high stockings are adequate,” says Dr. Fesmire.

“If we can save just one life by telling David’s story, that will make it all worthwhile,” says Melanie Bloom. “That’s why I keep talking about this. Because when we know more about DVT, we can save lives.”