High Blood Pressure (Hypertension) What Is It? Blood pressure
has two components: Systolic pressure is the top number. It
represents the pressure the heart generates when it beats to
pump blood to the rest of the body. Diastolic pressure is the
bottom number. It refers to the pressure in the blood vessels
between heartbeats. Blood pressure is measured in millimeters of
mercury (mmHg). So blood pressure would be expressed, for
example, as 120/80 mmHg. High blood pressure is diagnosed when
one or both of these numbers is too high. High blood pressure is
also called hypertension. Blood pressure is categorized as
follows: Normal: Less than 120/80 mmHg Prehypertension: 120/80
to 139/89 mmHg Stage 1 hypertension: 140/90 to 159/99 mmHg Stage
2 hypertension: 160/100 mmHg and above Usually, systolic
pressure increases as we age. However, after age 60, diastolic
pressure usually begins to decline. Prehypertension is not a
disease-yet. But it does mean you are at increased risk for
developing high blood pressure. Why wo