The No. 1 killer of women is also largely preventable -- heart disease.

As part of Heart Month, women are urged to wear red Friday to raise awareness of heart disease among women.

The American Heart Association began the Go Red For Women program in 2004. And the National Heart, Lung and Blood Institute is promoting The Heart Truth program, which includes Dress Red Day and National Wear Red Day.

"Last year, we discovered an alarming fact -- that women still don't know heart disease is their No. 1 killer," said Dr. Alice Jacobs, former president of the American Heart Association. "In fact, more women still believe that cancer is the greatest health problem facing them today."

About 80 percent of women ages 40 to 60 have one or more risk factors for heart disease, according to the NHLBI. Having just one risk factor can raise the risk of heart disease twofold.

Women can control many risk factors, including high blood pressure, high blood cholesterol, diabetes, smoking, being overweight or obese and being physically inactive.

"It is vitally important for women to talk to their doctors about their risks for heart disease and to take action today to lead a heart healthy life," said Dr. Elizabeth Nabel, NHLBI director. "Women are role models for their children and families, and as women improve their heart health, they can help improve the health of our nation."

In Boston, the Leonard P. Zakim Bunker Hill Bridge will be lit in red lights for the next 10 days as a tribute to the "Go Red for Women" campaign.

The campaign is more than just a slogan for Diane Famiglietti, 44, of Peabody, Mass. She is a heart attack survivor who never knew her risks, and it nearly killed her, reported WCVB-TV in Boston.

When Famiglietti was 39, she was a very active mother of four, except that she was smoking two to three packs of cigarettes a day.

"One day my jaw hurt, like gritting my teeth all day. Pain was in my jaw, like clenched, and my arms were heavy," she said.

An emergency room doctor said she had no typical signs of heart trouble and sent her home.

"I did not know there were different signs for men and women," Famiglietti said.

A few days later, she was back at the emergency room.

"I saw another doctor and he said, 'I could be completely wrong, but I think you're having cardiac arrest,'" Famiglietti said.

Tests revealed that Famiglietti had quietly suffered several heart attacks. But the worst was to come. During a stress test, Famiglietti suffered a massive heart attack.

"I was clinically dead, I think it was five minutes," said Famiglietti.

Not only is heart disease the No. 1 killer of women, it can be harder to diagnose in women.

"This is an issue of raising awareness not only amongst women, but amongst health care providers," said Dr. Paula Johnson, of Brigham and Women's Hospital in Boston. "All kinds of physicians who have primary contact with patients and emergency department physicians are clearly a very important group."

Six years later, Famiglietti no longer smokes and has lost 35 pounds.

"I've changed my life, my lifestyle. It's not a diet, it's better choices, healthier living. I walk around the block -- a mile, not a marathon -- to keep me active," said Famiglietti.

Famiglietti is on a mission for other women as well.

"It can happen to anyone -- young or old. You need to not be dismissed. You need to know what to look for," she said.

Additional Resources:

• Go Red For Women
• The Red Dress Project
• The Heart Truth
• Ways To Show Your Support