Measuring Blood Pressure

Your blood pressure normally rises and falls throughout the day. However, if your blood pressure stays high for a long time, it can damage your heart and lead to health problems. Chronic, or long-lasting, high blood pressure is also called hypertension.

Measure your blood pressure regularly to help your health care team diagnose any health problems early. You and your health care team can take steps to control your blood pressure if it is too high.

Why do I need to measure my blood pressure?

Measuring your blood pressure is the only way to know whether you have high blood pressure. High blood pressure has no warning signs or symptoms, and many people do not know they have it.

Nurse taking a woman's blood pressure reading.

A health care team member can measure your blood pressure in a doctor’s office.

Where do I get my blood pressure checked?

You can get your blood pressure measured

  • By a health care team member at a doctor’s office.
  • At pharmacies that have digital blood pressure measurement machines.
  • With a home blood pressure monitor that you can use yourself.

How do health care professionals measure my blood pressure?

First, a health care professional wraps an inflatable cuff around your arm. The cuff has a gauge on it that will measure your blood pressure. The health care professional then inflates the cuff to squeeze your arm.

The health care professional will slowly let air out of the cuff while listening to your pulse with a stethoscope and watching the gauge. This process is quick and painless.

The gauge uses a unit of measurement called millimeters of mercury (mmHg) to measure the pressure in your blood vessels.

Man taking his blood pressure reading at home.

Talk with your health care team about how to measure your blood pressure at home.

How can I measure my blood pressure at home?

Talk with your health care team about regularly measuring your blood pressure at home, also called self-measured blood pressure (SMBP) monitoring.

SMBP means you regularly use a personal blood pressure measurement device away from a doctor’s office or hospital—usually at home. Most home blood pressure monitors are easy and safe to use. A health care team member can show you how to use one if you need help.

Evidence shows that people with high blood pressure are more likely to lower their blood pressure if they use SMBP combined with health care team support than patients with high blood pressure who don’t use SMBP.2

Learn more about SMBP. Cdc-pdf[PDF – 1 MB]External

What do blood pressure numbers mean?

Blood pressure is measured using two numbers.

The first number, called systolic blood pressure, measures the pressure in your blood vessels when your heart beats.

The second number, called diastolic blood pressure, measures the pressure in your blood vessels when your heart rests between beats.

If the measurement reads 120 systolic and 80 diastolic, you would say, “120 over 80,” or write, “120/80 mmHg.”

Which number is more important?

Both the systolic (the first number) and diastolic (the second number) numbers are important. A health care professional can use either number to make a diagnosis of high blood pressure.

However, health care professionals sometimes look at high systolic blood pressure levels as a bigger risk factor for heart disease. As people age, their systolic blood pressure levels typically increase.

Blood Pressure Levels
Blood Pressure Levels1
Normal Blood Pressure Less than 120/80 mmHg
At Risk for High Blood Pressure

(Prehypertension)

Between 120/80 mmHg and 139/89 mmHg
High Blood Pressure (Hypertension) More than 140/90 mmHg

What are normal blood pressure numbers?

A normal blood pressure level is less than 120/80 mmHg.1

No matter your age, you can take steps each day to keep your blood pressure in a healthy range.

What is elevated blood pressure (prehypertension)?

People with elevated blood pressure levels in between 120/80 and 139/89 mmHg are at high risk for high blood pressure.1

Elevated blood pressure is a condition called prehypertension.

You can help prevent high blood pressure by managing any health or medical conditions you have and making healthy lifestyle choices.

What is high blood pressure?

A high blood pressure level is 140/90 mmHg or more.1 High blood pressure is also called hypertension.

You can help control your high blood pressure by making healthy lifestyle changes and, in some cases, taking certain medicines.

Talk to your health care team right away if you think you have high blood pressure. You can take action to help lower your risk of heart disease, also sometimes called cardiovascular disease (CVD).

How often should I measure my blood pressure?

Talk with your health care team about how often you should have your blood pressure measured or measure it yourself. People who have high blood pressure may have theirs measured more often.

References

  1. National High Blood Pressure Education Program. The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure Cdc-pdf[PDF – 223 KB]External. Bethesda, MD: National Heart, Lung, and Blood Institute; 2003.
  2. Uhlig K, Balk EM, Patel K, Ip S, Kitsios GD, Obadan NO, et al. Self-Measured Blood Pressure Monitoring: Comparative Effectiveness. Comparative Effectiveness Review No. 45. (Prepared by the Tufts Evidence-based Practice Center under Contract No. HHSA 290-2007-10055-I.) AHRQ Publication No. 12-EHC002-EF. Rockville, MD: Agency for Healthcare Research and Quality, U.S. Department of Health and Human Services; 2012.