President Fords historic trip and fall down the steps of Air Force One. 1  People & Blogs. 2  Standard YouTube License.
The bottom number, called the diastolic pressure, is the measurement as the heart relaxes between beats. Normal blood pressure is a systolic pressure of less than 120 millimeters of mercury (mm Hg) and a diastolic pressure of less than 80 mm Hg, or 120/80 mm Hg, according to the American Heart Association (AHA). Having a blood pressure greater than 140/90 mm Hg is considered high blood pressure or hypertension. A blood pressure level between normal and hypertension, is called prehypertension, meaning it is higher than normal, but not high enough to be considered hypertension.
What is a low blood pressure reading? A low blood pressure reading is having a level that is 90/60mmHg, or lower. Only one of the numbers has to be lower than it should be to count as low blood pressure. In other words: if the top number is 90 or less (regardless of the botton number) this may be low blood pressure.