High blood pressure is truly a silent killer. In fact, a heart attack or stroke may be the first sign that you even have a problem. That’s why it’s so important to get your blood pressure checked every time you go to the doctor—especially if you’re a woman.

About 35 million American women have high blood pressure, and a third of them don’t know it. In part, experts say, the increase comes just because women are living longer and doctors are paying more attention to the problem. But less-benign factors—like the exploding use of anti-inflammatory medicines (which make your body retain salt) and ever-increasing waistlines—may be at play in what the American Heart Association (AHA) calls a rise in uncontrolled hypertension in women.

Fortunately, there are many ways to control your blood pressure, even without medication. And just knowing your numbers is half the battle, says Dan Jones, MD, president of the AHA. But that doesn’t mean fighting high blood pressure is a cinch. Here are the stories of three women whose high blood pressure took them by surprise. Think about them the next time that cuff goes around your arm.

Next page: Ignorance isn’t bliss