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 (mm Hg). So blood pressure would be expressed, for example, as 120/80 mm Hg.
High blood pressure is diagnosed when one or both of these numbers is too high. High blood pressure is also called hypertension.