Age makes us more susceptible to having a stroke, as does having a mother, father, or other close relative who has had a stroke.

You can't reverse the years or change your family history, but there are many other stroke risk factors that you can control—provided that you're aware of them. "Knowledge is power," says Dr. Natalia Rost, associate professor of neurology at Harvard Medical School and associate director of the Acute Stroke Service at Massachusetts General Hospital. "If you know that a particular risk factor is sabotaging your health and predisposing you to a higher risk of stroke, you can take steps to alleviate the effects of that risk."

Here are ways to start reining in your risks today to avoid stroke, before a stroke has the chance to strike.