About Blood Pressure
Blood pressure is a term referring to the amount of pressure (measured in millimeters of mercury, or mmHg) inside the blood vessels. The pressure is measured both as the heart is pumping blood through the vessels and when it is relaxed.
In order to measure blood pressure, a fabric cuff is wrapped around your arm and then slightly inflated. The healthcare provider reads the numbers from the gauge attached to the cuff as air is released from it. The two numbers are written like a fraction: one number on top (systolic pressure) and one on the bottom (diastolic pressure).
(Click Blood Pressure to learn more about this topic, including what happens when it is too high and factors that can affect a person's blood pressure.)