What Do the Terms SYS/DIA Mean?

SYS is short for “Systolic,” and is your systolic blood pressure in millimeters of mercury (mmHg). Systolic blood pressure is a measurement of the pressure on your arteries as your heart pumps blood. DIA is short for “Diastolic,” and is your diastolic blood pressure in mmHg. Diastolic blood pressure is a measurement of the pressure on your arteries in between heartbeats.