Measuring Blood Pressure

Each time your heart beats, it pumps blood into your arteries (the blood vessels that carry blood from your heart to the tissues and organs in your body). A blood pressure measurement is a test that measures the force (pressure) in your arteries as your heart pumps. Blood pressure is measured as two numbers: Systolic blood pressure (the first and higher number) measures pressure inside your arteries when your heart beats.; Diastolic blood pressure (the second and lower number) measures the pressure inside the artery when your heart rests between beats.; For example, a blood pressure reading of 120/80 means a systolic of 120 and a diastolic of 80.

Many things can change your blood pressure. It can increase or decrease based on: Whether you're resting or exercising; If you eat or drink foods with caffeine, alcohol, or tobacco; Your age; If you're taking certain medicines; Your position, such as whether you're sitting, lying down, or standing; If your blood pressure is high on several different measurements on different days, you might have high blood pressure, also known as hypertension. Around half of American adults have high blood pressure.

It increases the risk of life-threatening conditions, including heart attack and stroke. But high blood pressure rarely causes symptoms. A blood pressure measurement helps diagnose high blood pressure early, so it may be treated before it leads to serious complications.

Why this test is done

A blood pressure measurement is often included as part of a regular checkup. Everyone age 3 or older should have their blood pressure checked by their provider at least once a year.

If you have high blood pressure or are at higher risk for it, you may need testing more often. You may be at higher risk if you:

• Are 40 years old or older.
• Are overweight or have obesity.
• Have a family history of heart disease or diabetes.
• Have a family history of high blood pressure.
• Take birth control pills or other medicines that can increase your blood pressure.
• Are Black/African American. Black/African Americans are more likely than other racial and ethnic groups to have high blood pressure.

Your provider can tell you how often you should get your blood pressure checked.

You may also need to have your blood pressure checked:

• To see how well your blood pressure medicine is working (if you have high blood pressure)
• If you are being treated in the hospital
• To check if it's safe for you to have a medical or surgical procedure
• To check if it's safe for you to play sports or do other strenuous activities or jobs
• If you have symptoms of low blood pressure

How to prepare

Several things can increase your blood pressure measurement. Tell your provider if you take any medicines, since some medicines may affect your results.

To get a more accurate blood pressure measurement, avoid these things for at least 30 minutes before having your blood pressure taken:

• Exercise
• Alcohol
• Tobacco products
• Food or drinks containing caffeine

Also, make sure to go to the bathroom before the test.

Other names for this test

blood pressure reading, blood pressure test, blood pressure screening, sphygmomanometry