Bill Weir, the co-anchor of ABC's Nightline, made a shocking discovery while working on a story about full body scans this week: he himself is at major risk of having a heart attack.

Weir was interviewing Dr. David Agus, the man who treated both late Apple CEO Steve Jobs and cyclist Lance Armstrong, when he was offered a full CT scan as part of the TV report.

During the scan, however, Dr. Agus found a serious blockage in the main artery of Weir's heart. If he had left it untreated, he would probably have died in the next five years.

I was blown away, Weir said. He went to the gym every morning before work, and thought his heart would be in peak condition.

Turns out, that rigorous exercise early and then 10 hours of sitting is as dangerous as or more dangerous than smoking.

Bill Weir is genetically predisposed to heart disease, and his carefree diet helped undo many of the benefits regular exercise had given him. He is now urging others to undergo genetic testing and get their hearts checked out, and is hoping that others may benefit from the assignment that probably saved his life.

Weir's story is highly unusual. Journalists often cover life-threatening conditions that probably save lives. But it's rare that they cover a story that ends up touching them so personally, or that they can point to as an assignment that directly saved a reader from harm.

Some reporters, however, from My Cancer blogger Leroy Sievers to ABC's own Stacey Sager, would understand what Weir is going through.

Al Pefley For Blood Donation

Pefley is a staple in the Palm Beach, Fla. community, covering hard news like murders, shootings and mass foreclosures.

But Al Pefley is also a regular blood donor for fifteen years, recently hitting the ten gallon mark.

In an effort to increase awareness of 0 negative blood, which Pefley has and which is known as a universal donor source, the reporter agreed to jump ship and promote his story for

Since he covered his donations back in 2009, hundreds have become more aware of the importance and ease of donations, and Al Pefley points out that his work as a crimes reporter and his PSA as a donator may overlap far more than he realized.

I suppose some of the people that I end up covering in the stories may be some of the same people who would benefit from the blood that myself and others are giving, he noted.

These victims of crimes ang things may be the same people who need the blood [the most].

Stacey Sager: 'You can't put your head in the sand.'

Another journalist at ABC, Eyewitness reporter Stacey Sager was diagnosed with breast cancer thirteen years ago.

When she decided to undergo genetic testing several months back, she covered both the news that she did have a family history of breats cancer and ovarian cancer and its effect on her family for ABC Eyewitness News.

In October, she went on the air to discuss how her history, and the lack of adequate screening for cancer in the ovaries and fallopian tubes, meant that she was at high risk for a relapse.

She used the segment to raise awareness about family history's impact on cancer, and to encourage others to get checked out.

There's no doubt: genetic testing saved my life, she said. Sager also described how hard it was for her to face her own fear about dying, and to push forward with the uncomfortable and sometimes humiliating or painful treatments.

You can't put your head in the sand, she recalled Dr. Carol Aghajanian, her oncologist, saying. You can't put it off.

Leroy Sievers, Cancer Blogger

But perhaps the most famous case of a reporter learning and sharing of their own mortality is journalist Leory Sievers, who covers wars, genocides and natural disasters in more than a dozen countries before he was forced to tackle his most painful assignment of all: chronicling life after a cancer diagnosis for NPR.

The My Cancer Blogger, who passed away in 2008, was first treated for colon cancer in 2001.

Four years later, when the cancer returned, he decided to detail his experiences undergoing chemotherapy for NPR's Morning Edition, in a segment that aired Feb. 16, 2006.

Several months after the first commentary, those writing in to NPR pushed Sievers to write a second. Eventually, it became a regular series called Cancer World, which then morphed into a multimedia project known as My Cancer.

My Cancer encompassed a daily, blog, a weekly podcast, and, most important to Sievers, a growing cancer support and awareness community.

Sievers' work as a journalist covering his cancer kept him going when the treatment got rough, and Ellen McDonnell, an NPR director, recalled in his obituary that his transparency and rawness struck a chord with thousands of listeners.

Leroy gave voice to a topic that we are very uncomfortable with: death and dying, McDonnell said.

In the summer of 2008, a week before he turned 53 years old, Sievers was told that his cancer had exploded throughout his body. He passed away that August.

Bill Weir's Legacy

Bill Weir is unlikely to start a segment detailing his treatment for heart disease, but his on-air diagnosis alone was enough to make his name, and his story, a viral sensation.

As reporters, it's becomes easy to cover stories that impact people's lives in a more detached way: in fact, that's one of the reasons journalists are able to survive chronicling stories like genocides or drive-by shootings.

But sometimes, reporters are forced to face their own mortality, whether on a story or in their own lives, and feel the need to take that story and use it to help others.

Whether promoting blood donation like Al Pefley, encouraging genetic testing like Stacy Sager, or chronicling a life-changing and life-threatening diagnosis like Leroy Sievers, Bill Weir's coverage has likely saved lives. And that's the kind of direct influence that every reporter, no matter how detached, hopes to achieve in their lifetime.