An estimated one in 1,000 Americans are diagnosed each year with a DVT, according to the Centers for Disease Control and Prevention. The number of Americans with DVTs, including those undiagnosed, is estimated to be up to 600,000. As many as 100,000 deaths each year are directly or indirectly linked to a DVT.

Though I have flown farther and sat still in coffeehouses for longer in the past, the doctor told me the blockage most likely was the result of my weekend sojourn in Starbucks, exacerbated by the flight. I might also have been a bit dehydrated from the travel and the run.

Whatever my particular cocktail of factors, the effect was the same: Blocked, the blood built up along the walls of the vein, clotting. Similar to a crash on a highway, the clot slowed the blood that tried to snake around it. The blood piled onto the clot, making it bigger and the passageway narrower.

A DVT is not usually life-threatening, by itself. But if part of the clot breaks loose and is thrown back into the bloodstream to travel freely, eventually it may lodge in a passageway too small for it, such as those found in the lungs. The result, a pulmonary embolism (PE), can kill you.

More than one-third of DVT patients have PE’s, according to the Surgeon General’s Call to Action to Prevent Deep Vein Thrombosis and Pulmonary Embolism, issued in 2008. “Often, the first symptom of DVT is a fatal PE,” Dr. Elizabeth G. Nabel, director of the National Institutes of Health’s Heart, Lung, and Blood Institute wrote in the report.

DVT/PE is an underappreciated problem in our society, said Dr. Anthony Venbrux, professor of radiology and surgery and director of the vascular and interventional radiology division at the George Washington Medical Center, echoing the report’s findings.

“We tend to dismiss them, saying ‘I’ll take an ibuprofen or use a heating pad.’ ‘We,’ meaning everyone, including physicians,” Venbrux said. “A classic example is a physician who was an athlete and didn’t want to acknowledge that it was DVT in the upper extremity that he was experiencing.”

Early diagnosis is the key to a positive outcome, and diagnosis is not difficult or painful. Now, completely noninvasively, we can rule in or rule out a DVT with 98 percent accuracy using a Doppler ultrasound, Venbrux said. “In the old days, we would have to inject contrast dye.” Nonetheless, many DVTs are believed to slip through the cracks, dismissed or unrecognized.

“The tragedy of these diseases is that their diagnosis is easy to overlook because the signs and symptoms are often diffuse and difficult to recognize. In many cases, there are no clinically apparent signs at all,” Nabel said.

As I quickly learned, the default treatment is to let nature takes it course, assisted by an intense, steady regimen of blood thinners, which rob the blood of its ability to stick to the little red mound, which my body would slowly absorb. The flip side was that my blood also could not stick together well enough to scab should I sustain a bleeding injury.