The following chart shows blood pressure categories defined by the American Heart Association (AHA): (1)
NOTE: If the pressure is lower than that there is no reason for concern unless you are experiencing certain signs and symptoms: dizziness, fainting, nausea, fatigue, depression, blurred vision, dehydration, cold, pale skin or fast, shallow breathing.
Here is an example of how to read the blood pressure using the normal range upper limit example:
120/80 mm Hg (read as 120 over 80 millimeters of mercury)
Systolic pressure is the number on top (120) and is always higher of the two.
Systolic pressure (120) measures the pressure in the arteries when the heart muscle contracts (beats).
Diastolic pressure (80) measures the pressure in the arteries when the heart is re-filling with blood between contractions (beats).