LAS VEGAS (Ivanhoe Newswire) -- It's being called a public health crisis. It kills more people than HIV and breast cancer combined, but most of us don't even know what it is. About 2 million Americans have DVT, and it can kill in an instant. Are you at risk?

NBC reporter David Bloom died while he was reporting in Iraq. Deep vein thrombosis (DVT) is what took his life.

"Even in the midst of bullets and bombs, it ended up a blood clot that hit his lungs and took his life instantly," Melanie Bloom, David's wife and a national patient spokesperson for the Coalition to Prevent DVT, told Ivanhoe. "He was only 39 years old."

His wife is dedicated to get the word out before another family is torn apart by DVT.

DVT is a disease that starts with a blood clot that forms inside a deep vein -- most often in the lower leg.

"These clots can become dislodged and make their way to the lungs and cause problems there," Mike Metzler, M.D., a trauma & critical care specialist at Sunrise Hospital & Medical Center in Las Vegas, told Ivanhoe.

The clots can block arteries in the lungs and cause death. Risk factors include obesity, recent surgery, restricted mobility, respiratory failure and old age.

After David died, his wife learned he had an inherited blood disorder. That along with the cramped quarters inside this tank and dehydration -- all combined to be fatal.

"He called me from the desert one night," Melanie recalled. "He said, 'Well I'm outside sleeping tonight on the tank instead of inside the tank', and I said, 'Get back inside the tank where you'll be safe,' and he said, 'No, my legs have been cramping up. I just have to stretch them out.'"

Two days later, David died. But through his wife, he's still getting the word out.

To prevent DVT, patients can keep active, wear deep compression stockings, and in extreme cases, take blood thinners.