II. HOW HIGH IS HIGH?
The World Health Organization (WHO) and many experts agree that in individuals under age 65, a systolic blood pressure equal to or greater than 140 mmHg and a diastolic blood pressure of 90 mmHg or above is ab¬normal. Optimal systolic blood pressure is less than 120 mmHg and optimal diastolic blood pressures are less than 80 mmHg. In patients age 65–80 a systolic pressure greater than 165 on three or more readings weeks or months apart is considered hypertension. The Framingham Study and other studies indicate a significant increase in car¬diovascular risk in individuals with a blood pressure in the borderline range. An individual is considered to have high blood pressure if several readings exceed 140/90, especially if three consecutive readings are elevated. The risk at any level of hypertension, including borderline hypertension, is greatly increased by smoking or a high blood cholesterol. Mild hypertension is extremely common, and over a 10- to 15-year period increases the risk of stroke, heart attack, and heart failure. Clinical studies have documented that blacks develop organ damage (stroke, heart failure, and damage to the kidneys) much quicker than whites at the same level of hypertension.