High Blood Pressure
High Blood Pressure

High Blood Pressure Diagnosis

Screening tests

Everyone who’s age 3 or older should have their blood pressure checked by a healthcare provider at least once a year. Your provider measures your blood pressure to see if it’s in a healthy range. Regular checks can also show how well treatment for high blood pressure is working.

Video about the importance of getting your blood pressure checked regularly and understanding what your numbers mean so you can better manage your heart disease risk.

Getting ready for a blood pressure measurement

Your provider will measure your blood pressure to see if you have higher-than-normal blood pressure. A blood pressure measurement is easy and painless and can be done in the provider’s office or clinic or at home. The provider uses a gauge, stethoscope, or electronic sensor and a blood pressure cuff to measure your blood pressure.   

Prepare for the test by following a few simple steps:

  • Do not exercise, drink coffee, or smoke cigarettes for 30 minutes before the test.
  • Go to the bathroom before the test.
  • For at least 5 minutes before the test, sit in a chair and relax.
  • Make sure your feet are flat on the floor.
  • Do not talk while you are relaxing or during the test.
  • Uncover your arm for the cuff.
  • Rest your arm on a table so it is supported and at the level of your heart.

Even if you do prepare, your blood pressure reading may not be accurate if: 

  • You are excited or nervous. “White coat hypertension” refers to blood pressure readings that are higher in a provider’s office than readings at home or in a pharmacy. To detect this type of high blood pressure, your provider may review readings from the office and from other places.
  • Your blood pressure tends to be lower when measured at a provider’s office. This is called “masked high blood pressure.” When this happens, your provider will have difficulty detecting high blood pressure. Your provider can recognize this type of high blood pressure by looking at readings taken at the office and at home, especially at night.
  • The wrong blood pressure cuff was used. Your readings can be different if the cuff is too small or too big. It is important for your provider to use the correct pressure cuff for your sex and age.

You can also take your blood pressure at home or at a pharmacy. The Self-Measured Blood Pressure Fact Sheet has more information about how to measure your blood pressure outside of a provider’s office. If you take your own blood pressure at home, use an approved home blood pressure device to make sure the readings are correct.

What the numbers mean

Your blood pressure reading is made up of two numbers, the top,  systolic , number and the bottom,  diastolic , number. These numbers measure pressure in  mm HG  (millimeters of mercury). To learn more about systolic and diastolic pressure, visit How the Heart Works. For most adults, a healthy blood pressure is less than 120/80 mm Hg. Your blood pressure is considered high when you have consistent systolic readings of 130 mm Hg or higher or diastolic readings of 80 mm Hg or higher.

Talk to your provider if your blood pressure readings are consistently higher than 120/80 mm Hg.

NHLBI-supported research has shown that systolic blood pressure higher than 120 mm Hg can cause harm to health over time, including organ damage. Readings above 180/120 mm Hg are dangerously high and require immediate medical attention.

For children younger than 13, blood pressure readings are compared with readings that are common for children of the same, age, sex, and height.

Blood Pressure Levels

Blood Pressure CategorySystolic and Diastolic Pressure (mm Hg)
NormalLess than 120 systolic pressure AND Less than 80 diastolic pressure
Elevated120 to 129 systolic pressure AND Less than 80 diastolic pressure
High Blood Pressure Stage 1130 to 139 systolic pressure OR 80 to 89 diastolic pressure
High Blood Pressure Stage 2140 or higher systolic pressure OR 90 or higher diastolic pressure
Hypertensive Crisis 
Higher than 180 systolic pressure OR Higher than 120 diastolic pressure
Contact your provider immediately.

How will my provider find out if I have high blood pressure?

Your provider may diagnose high blood pressure if your blood pressure readings are consistently high. You may also need tests to look for medical conditions that cause high blood pressure or to see if high blood pressure has affected your organs.

Medical history

Your provider will want to understand your risk factors and get general health information. They will ask about your eating patterns, physical activity level, sleep, body weight, stress, smoking status, and family’s health history. The information will help your provider work with you to set up a treatment plan. They will ask questions to see if your high blood pressure has caused any health problems. This will help them decide if you need other tests.

Confirming high blood pressure

You will need two or more blood pressure readings at separate medical appointments to diagnose high blood pressure.

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