This disease is the No. 1 killer of American women over age 25.

It kills five Maine women a day. (Nationwide, the death toll is one woman every minute of every day.)

An estimated 43 million American women are affected by it.

What medical condition are we talking about?

Heart disease.

If you’re surprised, you’re not alone. Education campaigns have raised consciousness of heart disease’s prevalence among women. However, its association with men is hard to shake.

Only one out of five women believes that heart disease is her greatest health threat. Many women still worry more about breast cancer, surveys show. The vast public debate sparked by actress Angelina Jolie’s recent announcement of her preventive double mastectomy bears this out as well.

MORE LETHAL TO WOMEN THAN TO MEN

Though we do not want to downplay the seriousness of breast cancer, we appreciated that during the discussion about Jolie’s surgery, some experts spoke up and noted that cancers of all kinds take fewer women’s lives each year than heart disease does.

Even many doctors don’t realize that heart disease, stroke and other cardiovascular disorders are a greater risk to women than to men, resulting in less aggressive efforts to diagnose and treat heart disease in women. The ultimate consequences are tragic: Since 1984, more women than men have died each year from heart disease.

It doesn’t have to be this way. Cardiovascular disease is largely preventable, but we must all pressure researchers, doctors and state and federal officials to work together to ensure Maine women’s heart health. Otherwise, we’ll all pay the cost in death, disease and avoidable emergency care.

RESEARCH LACKING

Until fairly recently, research on cardiovascular disease has focused almost exclusively on men. So researchers know much more about the best way to treat male heart patients than about the best way to treat female heart patients.

To remedy this disparity, scientists need to include more women in clinical drug trials, and their findings need to note the gender of the patients studied. Otherwise, it’s hard to draw valid conclusions about what treatments work for women. (Federal officials could help by increasing research funding and better enforcing mandates applying to women’s participation in federally funded clinical trials.)

Researchers also need to develop accurate tests for assessing women’s cardiac risk. Heart disease often looks different in women than it does in men: It shows up as problems not just with the major coronary arteries, but also with the smaller vessels that also nourish the heart. So some diagnostic tests falsely report that a woman is at low risk of heart disease when in fact the opposite is true.

PHYSICIAN EDUCATION

Because heart disease is so pervasive in women, physicians must educate themselves about the most common symptoms and ask about them as part of routine checkups (just as they’d ask a woman patient whether she’d found any lumps during her monthly breast exams). Crushing chest pain is the classic symptom of a man having a heart attack. A woman is more likely to report pain in the neck or shoulder, extreme fatigue, cold sweat or shortness of breath.

And when a doctor recognizes that a woman has had a heart attack or is at risk of one, he or she must take direct and aggressive action. We don’t know as much as we should about effective treatments for women, but we do know that statins and beta blockers are life-saving measures for cardiac patients of both genders.

Unfortunately, many of the women at highest risk of heart disease (black, Hispanic and low-income women) have little access to preventive care or diagnostic tests.

PREVENTIVE MEASURES UNDERFUNDED

They’re among the millions of women nationwide — and thousands in Maine — who can’t afford to visit a doctor because they have no insurance.

Lifestyle factors, including whether one smokes and what one weighs, contribute a lot to heart disease risk. More than 17 percent of Maine women are smokers, and more than 56 percent are obese or overweight. But many of them can’t afford to take the steps that would lower their chances of developing cardiac ailments, like quitting smoking and eating more-healthy food.

Why? The prescription drugs found to be the most effective treatment for people who want to stop smoking are not cheap if you don’t have insurance. Food that is better for you, like fruit and vegetables, is more expensive than food that is bad for you.

Poverty is higher among women than among men, so cuts in programs that benefit the poor have a disproportionate impact on women. When the state government eliminates funding for Medicaid’s smoking-cessation benefit — and the federal government reduces spending on food stamps — they place more Maine women at risk of developing cardiovascular disorders.

Then, instead of paying for prevention efforts, we all wind up footing the bill for more-costly emergency care after a woman has a heart attack.

Improving women’s heart health must be a team effort. Researchers must develop effective tests and treatments. Physicians have to be aware of women’s risk of heart disease, inquire about the symptoms during yearly exams and aggressively diagnose and treat the symptoms they see. Finally, government needs to support research into heart disease at the federal level and better fund preventive efforts at the state level. It won’t be easy or cheap, but the stakes are too high for us to delay immediate action.