Although most women don't realize it, heart disease is a woman's deadliest foe.

Heart disease is the leading cause of death in women in the United States, according to the American Heart Association. It claims the lives of approximately 500,000 women each year - 10 times more than women who die of breast cancer. In fact, heart disease surpasses the combined death rates from breast, ovarian and cervical cancers.

These statistics are a stark reminder to women that heart disease is not just a man's disease anymore. In fact, the number of female deaths from cardiovascular disease has exceeded those of males every year since 1984. The difference in deaths now is nearly 67,000 per year, says the American Heart Association.

As women grow older, their risk of heart disease increases. Once a woman reaches the age of menopause, that risk jumps sharply due to the reduced level of estrogen in her body. Estrogen helps a woman's body protect against heart disease. A reduction in estrogen causes changes in the walls of the blood vessels, making it more likely for plaque (fatty deposits) and blood clots to form. Lower estrogen levels also cause changes in the level of fats in the blood, increasing the amount of LDL ("bad") cholesterol in the blood and decreasing the amount of HDL ("good") cholesterol.

Other risk factors for heart disease in women (and men) include smoking, diabetes, high blood pressure, obesity and high cholesterol.

Women often delay seeking medical treatment because they don't recognize the symptoms of heart disease, which may differ from men. Although many women experience chest pain during a heart attack, it's often described as a burning sensation rather than a squeezing pain in the chest. Sometimes the pain isn't in the chest, but is centered in the arm, the stomach, back or jaw. Women may also feel like they are short of breath or anxious, rather than in pain. As a result, women don't realize what these symptoms mean and delay seeking treatment.

Fortunately, there are many things that women can do to control their risk factors for heart disease. These include:

• If you smoke, quit
• Reduce the amount of fat and cholesterol in your diet
• Control your blood pressure and diabetes
• Lose weight if you are overweight
• Exercise regularly (at least three times a week)
• Discuss your family health history with your physician and ask about your cholesterol level (both HDL and LDL), your triglycerides and your blood pressure