Though men are still perceived to comprise the majority of heart disease sufferers, as women age, their heart attack risk starts to equal that of men's. According to the American Heart Association, heart disease and stroke are the leading causes of death among older women, with about twice as many dying of cardiovascular disease than all the cancers combined. Worse still, since the symptoms of heart disease manifest themselves slightly differently in women, they're more easily misdiagnosed and less likely to get help as soon as those symptoms surface. So what are the factors that contribute to a woman's likelihood for developing heart disease? Here are three:

Menopause. Studies have shown that heart disease risk in women rises after the onset of menopause. Scientists are still trying to figure out why that is, but it has been proposed that the loss of natural estrogen may be a culprit. Doctors once prescribed hormone-replacement therapy (HRT) to decrease this risk, as well as alleviate the symptoms of menopause. But in light of research that has surfaced since the Women's Health Initiative landmark study in 2002, which claimed that HRT caused more harm-increasing the likelihood for breast cancer and, ironically, heart disease-than good, the practice is no longer recommended by institutions such as the American Heart Association.

Obesity. In most cultures, women are more likely than men to be obese, and obesity plays a major role in heart disease since it increases blood pressure and raises bad cholesterol levels while lowering good cholesterol. Research published in the September 2006 issue of American Journal of Public Health showed that women suffered the consequences of obesity much more so than did men. In fact, whereas overweight men lost a collective 47,000 years of life due to related illnesses, overweight women were deprived of 1 million years. And the mortality rate for obese women over 45 far surpasses their male counterpart's.

Physical inactivity. The tendency for more women to suffer from obesity is attributable in part to a lack of exercise. The American College of Sports Medicine released a study at the beginning of 2007 in which women reported that they're less physically active, with an inactivity rate of 15.1 percent versus 12.3 percent rate reported by men. Regular exercise-most experts recommend at least 30 minutes of moderately strenuous activity about five times a week-will boost the efficiency of your cardiovascular organs, decrease your blood pressure and resting heart rate, and rev up your metabolism, which will help you burn fat faster, thus lowering your risk for heart disease.