How High Blood Pressure is Diagnosed

Updated:Sep 16,2016
How HBP is diagnosed

To find out if you have high blood pressure, also called hypertension, have your blood pressure tested by a healthcare professional.

Good news — it's easy!

Simple, quick and painless, a blood pressure test can be done at a healthcare provider's office, hospital, clinic, nurse's office, company clinic or health fair. Healthcare professionals use a medical instrument called a sphygmomanometer, which in layman's terms is known as a blood pressure monitor. This bicep cuff monitor yields the most accurate reading among various types of monitors. Watch an animation of how a blood pressure test is performed.

During the test, a rubber cuff is placed around the upper arm (typically the right arm) before being manually or electronically inflated. Once inflated, the cuff compresses a larger artery in the bicep, momentarily stopping blood flow.

Next, air in the cuff is slowly released while the healthcare professional measuring the blood pressure listens with a stethoscope or monitors an electronic readout. When the blood starts to pulse through the artery, it registers sounds that continue until pressure in the artery exceeds the pressure in the cuff. The healthcare provider watches the monitor's gauge before recording two measurements:

  • Systolic pressure
    Systolic pressure is the pressure of the blood flow on the artery walls when the heart beats or contracts, forcing blood out into the body. The number on the gauge when the first heartbeat is detected is the systolic pressure. It is the higher of the two pressures in a reading, and it is the number that appears on top.
  • Diastolic pressure
    Diastolic pressure is the pressure on the artery walls between heartbeats, or when the heart relaxes between contractions. The diastolic pressure is the number recorded when the last sound is registered. It is the lower of the two pressures in a reading, and this number appears on the bottom.

AHA Recommendation

Optimal blood pressure is less than 120/80 mm Hg (systolic pressure is 120 AND diastolic pressure is less than 80). For optimal health, the American Heart Association recommends adults to maintain a blood pressure of less than 120/80 mm Hg millimeters of mercury. Starting at age 20, have a blood pressure screening at your regular healthcare visit or once every 2 years, if your blood pressure is less than 120/80 mm Hg. Learn more about the different blood pressure categories.

This content was last reviewed on 08/04/2014.