Understanding Blood Pressure
Blood pressure is typically recorded as two numbers, written as a ratio like this: 117/76
Read as "117 over 76 millimeters of mercury"
The top number, which is also the higher of the two numbers, measures the pressure in the arteries when the heart beats (when the heart muscle contracts).
The bottom number, which is also the lower of the two numbers, measures the pressure in the arteries between heartbeats (when the heart muscle is resting between beats and refilling with blood).