Like everyone else, I notice the signs of aging, including the gradual changes around the hips and eyes that tell me I'm not immortal. Some effects of aging aren't so slow or subtle, and women going through menopause know this best of all.

This is an intensely personal experience for many women, compounded by health issues that are difficult to understand or keep track of -- let's not kid ourselves, even health professionals are challenged by the rapid changes and long-term consequences of menopause.

While menopause is a critical time for women for many reasons, it's easy to overlook the fact that it is a turning point in heart health. Many people understand that women are at lower risk of heart disease before menopause, but far fewer realize that women quickly catch up to men after menopause.

Heart disease is the number one cause of death and disability in women, and more women than men die of heart disease overall.

The symptoms of heart disease can be more challenging to detect in women, and this means that severe heart disease is much more frequently overlooked or misdiagnosed in women than in men.

Menopause occurs in women when menstruation has ceased and the ovaries stop producing estrogen. Lack of estrogen produces all of the aggravating symptoms classically associated with menopause -- hot flashes, difficult sleeping, and depression -- and also other long-term adverse consequences like osteoporosis. So it is no surprise that estrogen has been prescribed for women to suppress menopausal symptoms and prevent bone loss.

It was not that long ago that physicians thought estrogen would reduce the risk of heart disease, especially heart attacks, in women who took estrogen replacement therapy. Because women's heart risk "catches up" with men after menopause, many people assumed that estrogen protected the heart from heart attacks and other problems, just as it protected bones from getting weak.

This wasn't just a wild idea. Many studies pointed to a beneficial effect of estrogens on the heart. However, when a definitive study, the Women's Health Initiative, was performed to test this idea in women, the results were surprising and indicated no heart health benefit in women taking estrogen replacement therapy after menopause.

These results, published in the Journal of the American Medical Association in 2002, remain controversial. Some physicians and public health experts interpreted these studies to indicate that estrogen replacement therapy could increase the risk of heart disease, but most experts felt that this study simply told us that estrogen replacement therapy did little either to harm or help the heart.

More recent analyses from this same study indicate that estrogen replacement therapy does not increase the development of blocked arteries in the heart, especially in women younger than 60 who take estrogen replacement therapy.

I don't think there is a good reason for all women to routinely begin estrogen replacement therapy after menopause. I certainly don't think there is good evidence that estrogen will reduce the risk of future heart events in post-menopausal women. However, women who take estrogen to reduce the symptoms of menopause or to prevent bone loss are probably not doing anything in hurt their heart either.

In other words, the most important thing is that women have a frank conversation with their physician about the benefits as well as the risks of estrogen replacement therapy to decide what is best for them.

I've focused on the issue of estrogen replacement therapy for post-menopausal women to reduce their risk of heart problems because this is the most complicated and controversial issue right now. However, there are a lot of things that women can do to protect their heart that are not nearly so controversial.

Women should not smoke, should exercise at least 30 minutes a day five times a week, and should follow a heart-healthy diet.

Once women reach menopause, it is especially important to be sure that cholesterol levels and blood pressure are normal. Most importantly, it is crucial for women to recognize that their risk of heart disease goes up markedly after menopause, and that there is a lot that can be done to reduce this risk.