When you take your blood pressure, the measurement has two numbers. The top number is the systolic blood pressure. The bottom number is the diastolic blood pressure.

For example, the blood pressure in this picture is 120/80. That would be said as “120 over 80."

Systolic blood pressure is the amount of pressure in your blood vessels while your heart is beating. Diastolic blood pressure is the amount of pressure in your blood vessels while your heart is resting between heartbeats. That’s why your diastolic blood pressure is lower than your systolic blood pressure.

Both numbers are important when it comes to understanding your blood pressure and your heart health.

Systolic sits on top and diastolic goes down below.