What is a normal reading on a blood pressure chart?

Normal systolic and diastolic values on a blood pressure chart read below 120 and below 80 millimeters of mercury, respectively, according to the American Heart Association. The systolic value measures arterial pressure as the heart beats, while the diastolic value is that of arterial pressure as the heart is resting.

Higher than normal readings on a blood pressure chart may indicate prehypertension, hypertension or a hypertensive crisis depending on their values, explains the American Heart Association. Doctors usually take several readings and, if the results confirm the condition, start the patient on a treatment plan that includes medication and lifestyle changes.