Most causes for waking up with a racing heart aren't serious. But some may require treatment. Learn the causes of heart palpitations and when to see a doctor.

The Polar H9 costs less than other HRMs that pack more features, but it still covers all the basics. It's comfortable, waterproof, and washable, and you can pair it with a phone, a running watch ...

Read current medical research on risk factors, causes and prevention of heart disease, strokes, and peripheral arterial disease. What new treatment options are under development?

Exercise can temporarily increase blood pressure or lower it slightly. Learn more about when to talk to your doctor, blood pressure readings, and safety tips.