Heart disease is the leading cause of death for women in this country (and now the world); it kills more every year than all cancers combined.

Sometimes, the first symptom of heart disease is sudden death. That’s why prevention is so important. This type of heart disease, “coronary artery disease,” is largely preventable. But to practice prevention, you need to know you’re at risk.

And women are far less likely to be aware of their risk.

Women are less likely to act when experiencing warning signs or symptoms of a heart attack. New symptoms of chest discomfort, shortness of breath, or fatigue that occur when you are physically active and that are relieved by rest can be signs that you have unstable heart disease.

Sudden or more gradual onset of unremitting chest pain is the most common symptom of a heart attack, but 45 percent of women having heart attacks do not experience chest pain. The heart can’t “feel” pain, so the brain has to make up a place for it to be coming from. This is called “referred” pain. Heart attack pain can be perceived as pain coming from the neck, throat, shoulder, arm or back. Symptoms of a heart attack can also mimic heartburn, or can cause excessive sweatiness or just profound fatigue. Women are more likely to experience these atypical symptoms.

Women wait longer than men before going to an emergency room. We are less likely to call 911. A recent AHA survey found that only 53 percent of women who believe they are having a heart attack would call 911. A Tufts University study of EMS data from Texas found that women are 55 percent more likely to suffer delays after they call 911 for chest pain.

Most people know that something is wrong when they are experiencing a heart attack. It is quite common for them to share this feeling with a nearby person. The worst person to tell is your spouse, as they are the most likely to say, “Relax, you’ll be fine.” A stranger off the street is more likely to respond by saying that you should get checked out.

If you think you are having a heart attack, don’t call your doctor, don’t call your best friend—call 911 first.

Not only do women have more atypical symptoms and wait longer before going to an emergency room, we’re also less likely to have a diagnostic electrocardiogram during a heart attack.

Not surprisingly, we’re less likely to be diagnosed correctly. But even if we are diagnosed correctly, we’ll be less likely to receive all the life-saving therapies available to treat heart attacks today. And even if the decision is made to give these therapies, they will be given, on average, at a significant time delay compared to men.

For those of us who treat heart attacks, we have a saying: “Time is muscle.” Even if you control for all of these variables, a woman will still be more likely to die from her heart attack than a man. And it is the youngest women who have the greatest death discrepancy rates compared to the youngest men – and we don’t know why.

Death rates due to heart disease have been declining in this country for decades, but our most recent data show that death rates due to heart disease have leveled off in our youngest adults, and may even be increasing in young women ages 29-45.

A woman who is discharged home after a heart attack will be less likely to be prescribed all the medications known to improved survival in heart attack patients.  She will be referred to a cardiologist less often, and will be enrolled in cardiac rehab less often.

Depression is more common in women than in men, and women who are depressed are many times more likely to die in the first few months after a heart attack. Cognitive behavioral therapy and psychotropic medicines are clearly helpful in some women, but not all. In particular, being physically active, listening to pleasing music, and socializing have been shown to be helpful. Combining all three at once—say, by taking a brisk walk with a pal while sharing favorite music on your iPod—is even more of a winner.

Your life doesn’t have to end by a heart attack or after a heart attack. Indeed, some women lucky enough to survive their heart attacks live healthier and happier and better than ever before.  I take care of several amazing women who can testify to that. But women need to know their risk, they need to practice prevention, and they need to act if they think something is wrong. We would much rather treat indigestion in the ER instead of missing a heart attack. As women, we need to partner with doctors we can trust, but we need to be our own health advocates first.