You’ve probably had your blood pressure taken at the doctor’s office. The nurse reads off two numbers, say, for example, “115 over 75.” The first number (“systolic”) represents the pressure in your arteries as your blood pumps from the heart; the second number (“diastolic”) is the pressure in your arteries while the heart is resting between beats. The American Heart Association defines “normal” blood pressure as a systolic pressure under 120 and a diastolic pressure under 80—or 120/80. Anything above 140/90 is considered hypertensive. Values in between are considered prehypertensive.
