Blood pressure level chart in mmHg
Blood pressure reading includes systolic and diastolic pressure values. Systolic blood pressure is the peak pressure, when the heart contracts while pumping blood. Diastolic blood pressure is the drop in pressure, when the heart is at rest between beats.
Often blood pressure is noted as the systolic number above or before the diastolic, such as 120/80 mmHg. (The mmHg is millimeters of mercury, the unit to measure pressure.)