This is a rush transcript from "On the Record ," March 10, 2009. This copy may not be in its final form and may be updated.

GRETA VAN SUSTEREN, FOX NEWS HOST: NBC reporter David Bloom died April 6, 2003, covering the Iraqi war. He was there in the midst of the violence because he wanted you to see the war from the war. Journalists like David know there is always a real risk of death when covering wars, but David was not killed by bombs or gunfire. David, died of deep vein thrombosis, also known as DVT.

David's widow Melanie Bloom is a national patients spokesperson for the coalition to prevent DVT. She joins us live.

Melanie, it's nice to see you. And, I should say, how are the children?

MELANIE BLOOM, WWW.PREVENTDVT.ORG: Good to see you too, Greta. The children are doing really well. Thanks for asking.

VAN SUSTEREN: You know, all of us always admired David. He was always fun, a great guy to compete with because he was such a nice, decent guy.

And as much as I admire him, I must say I admire you more for taking this tragedy and now trying to help other. So tell us about DVT and what you are doing.

BLOOM: Thank you for that. Yes, six years ago, David passed away, as you know, covering the war in Iraq for NBC news, and it was shocking. The bitter irony is that he died in the midst of a war from something inside his own body.

And, essentially, DVT is deep vein thrombosis, or a blood clot that forms in the leg, can travel and hit the lungs, and become suddenly fatal, as in David's case.

After he passed away--I had never heard of DVT until I got the call in the middle of the night. But after he passed away, I learned that more lives are lost from complications of DVT here in our nation than from AIDS and breast cancer combined -- 300,000 people die each year.

And it's preventable. So I really wanted to get that word out so other families don't have to endure this pain and tragedy that the girls and I had to go through.

Watch Greta's interview with Melanie Bloom

VAN SUSTEREN: Did David develop this because he was sitting in a cramped tank and he had been flying on airplanes? Looking at him, he was a 39-year-old guy at the time. I can see him by closing my eyes. He seemed like a very fit guy. Why did he develop this?

BLOOM: Exactly, and that is a great question. Why did he? He was 39 years old, the picture of health. What we learned after the fact is that he did have several risk factors. One, the long haul flights that you mentioned, anything that restricts the blood flow in your legs. Certainly sitting on air plane for a long time or even sitting at your computer desk for a long time can reduce the circulation.

Dehydration -- they were low on water supply along the front lives of the battlefield, and that causes your blood to thicken and become more sluggish.

After he passed away an autopsy revealed a genetic predisposition to clotting, which he was totally unaware of.

Important to note, though, that out of the 300,000 deaths each year, only a very small percentage actually have a genetic component.

So you need to know-there is a whole list of the other risk factors-- being over 40, being overweight, smokers. There are many other risk factors, and we encourage people to know what those risk factors are.

Our Web site, preventdvt.org, lists all of the risk factors for DVT.

VAN SUSTEREN: I can only imagine how much you miss him and the children, because even looking at the video, I remember the fun times when I would run into him.

I'd always tease him, because we would do White House shots, and I would walk behind him in his shot so that I could be on television and just sort of tease him and show up on another network.

But he was always fun. He was always so good natured that it's so hard to look at a guy who was at the top of his game. He was so innovative in what he was doing and the covering the war.

I guess it takes someone like David to have his widow go out and save more lives, and that is sort of consistent in an odd way, is it not?

BLOOM: Well, I hope that that's what we're doing. I think that is what we are doing with our coalition to prevent DVT, and doing it in his honor and his memory. He did have a passion and a zeal for what he did, and he cared a lot about the soldiers and his career as a journalist.

So I hope I'm honoring that memory by doing this work.

VAN SUSTEREN: So one of the things, we should probably wear those tight socks on airplanes, right, on those long flights?

BLOOM: Absolutely -- compression stockings. The doctor can fit someone who is at risk for DVT with compression stockings. Even pumping your feet if you are sitting along time, drinking a lot of fluid, and being aware of warning signs and symptoms.

David, had a leg cramp that he sort of casually mentioned, and only two days after mentioning that leg cramp to me on a phone call from the desert, he died. Having the leg pain and knowing what to do with those warning signs and symptoms.

VAN SUSTEREN: Well, Melanie, as I said, I admired David and liked him, but I actually admire you more for taking a horrible tragedy and saving other lives as well.

So thank you very much, and--

BLOOM: Thanks for having me, Greta.

VAN SUSTEREN: Come up back Melanie, thank you.

BLOOM: I will.

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