what is a prehypertension blood pressure reading?
Only one of your blood pressure readings needs to be in this range to diagnose prehypertension, so if your systolic blood pressure (upper number) is between 120 mmHg and 139 mmHg, or if your diastolic blood pressure (lower number) is between 80 mmHg and 89 mmHg you have prehypertension (or high normal blood pressure).