Blood pressure reading includes systolic
and diastolic pressure values. Systolic blood pressure is the pressure
peak when the heart beats while pumping blood. Diastolic blood pressure
is the pressure drop when the heart is at rest between beats.
Often
blood pressure levels are written with the systolic number above or
before the diastolic, such as 120/80 mmHg. (The mmHg is millimeters of
mercury the unit used to measure pressure.)
Blood pressure level chart in mmHg
| Category | Systolic | | Diastolic |
| Normal | less than 120 | and | less than 80 |
| Pre Hypertension | 120 to 139 | or | 80 to 89 |
| Hypertension (stage 1) | 140 to 159 | or | 90 to 99 |
| Hypertension (stage 2) | greater or equal to 160 | or | greater or equal to 100 |
When
systolic and diastolic blood pressures fall into different categories,
the higher category should be used to classify blood pressure levels.
For example, 150/79 mmHg would be stage 1 hypertension.
