Blood pressure test

Overview

A blood pressure test measures the pressure in the arteries as the heart pumps. A blood pressure test may be done as a part of a routine health checkup or as a screening for high blood pressure, also called hypertension. Some people use home monitors to check their blood pressure at home.

Why it's done

A blood pressure test is a routine part of most health checkups. Blood pressure screening is an important part of general healthcare.

How often you should get your blood pressure checked depends on your age and overall health.

• People age 18 to 39 with optimal blood pressure and no heart disease risk factors should have a blood pressure test at least once every 2 to 5 years.
• People age 40 and older — or younger with an increased risk of high blood pressure — should have a blood pressure test every year. Risk factors for high blood pressure include obesity and being Black.
• People who have long-term health conditions, such as high or low blood pressure or heart disease, may need to have blood pressure tests more often.

The American Heart Association (AHA) and other organizations recommend that people with high blood pressure monitor their blood pressure at home. Regularly checking blood pressure at home helps your healthcare team know if your treatment is working. Ask your healthcare professional how often you need to check it. But checking your blood pressure at home isn't a substitute for visits to your healthcare professional.

Most pharmacies, medical supply stores and some websites sell home blood pressure monitors. Experts recommend an automatic or electronic device. Your healthcare professional can help you pick the monitor that's best for you.

It's a good idea to keep a record of your home blood pressure readings. Also have a healthcare professional check your blood pressure device once a year to make sure you are getting accurate readings.

Risks

A blood pressure test is simple, quick and usually painless. However, the blood pressure cuff squeezes the arm while it inflates. Some people find this slightly uncomfortable. The feeling lasts for only a few seconds.

How you prepare

No special preparations are usually needed for a blood pressure test. But the following steps may provide the most accurate measurement:

• Do not smoke, exercise or use caffeine for 30 minutes to an hour before the test. Such activities increase blood pressure and heart rate.
• Wear a short-sleeved shirt so that the blood pressure cuff can be placed more easily around your arm. A rolled-up sleeve that's tight around your arm can affect the reading.
• Relax in a chair for at least five minutes before the test. Your back should be supported against a chair. Try to be calm and not think about stressful things. Don't talk while your blood pressure is being taken.
• Tell your healthcare team about medicines you take. Some medicines may affect blood pressure.

What you can expect

During the procedure

A healthcare professional takes your blood pressure. The test is usually done while you are seated in a chair in a comfortable position. Do not cross your legs and ankles. Your arm should rest comfortably at heart level.

The blood pressure cuff goes around the top part of the arm. The bottom of the cuff is just above the elbow. It's important that the cuff fits. The reading can be inaccurate if the cuff is too big or too small.

Blood pressure readings can be taken with the help of a machine. This is called an automated measurement. When a machine isn't used, it is called a manual measurement.

• For a manual blood pressure measurement, the care professional places a device called a stethoscope over the major artery in the upper arm. The health professional can hear the blood flow through this device.
• The cuff is inflated with a small hand pump.
• As the cuff inflates, it squeezes the arm. Blood flow through the artery stops for a moment.
• The healthcare professional opens a valve on the hand pump. This slowly lets out air in the cuff and restores blood flow. The health professional continues to listen to blood flow and pulse and records the blood pressure.

For an automated blood pressure reading, the blood pressure cuff automatically inflates and measures the pulse. A stethoscope is not used.

After the procedure

If your blood pressure is high or low, you usually need at least three more blood pressure tests, spaced a week or so apart, to determine if you need treatment. Blood pressure can vary from moment to moment and day to day.

Results

Your healthcare professional can tell you your blood pressure results right away after the test.

Blood pressure is measured in millimeters of mercury (mm Hg). In general, hypertension is a blood pressure reading of 130/80 millimeters of mercury (mm Hg) or higher.

The American College of Cardiology and the American Heart Association divide blood pressure into four general categories. Ideal blood pressure is categorized as normal.

• Normal blood pressure. Blood pressure is lower than 120/80 mm Hg.
• Elevated blood pressure. The top number ranges from 120 to 129 mm Hg and the bottom number is below, not above, 80 mm Hg.
• Stage 1 hypertension. The top number ranges from 130 to 139 mm Hg or the bottom number is between 80 and 89 mm Hg.
• Stage 2 hypertension. The top number is 140 mm Hg or higher or the bottom number is 90 mm Hg or higher.

Blood pressure higher than 180/120 mm Hg is considered a hypertensive emergency or crisis. Seek emergency medical help for anyone with these blood pressure numbers.

Here's a look at blood pressure categories and what they mean. If the top and bottom numbers fall into two different ranges, the correct blood pressure category is the higher one.

* Ranges may be lower for children and teenagers. Talk to your child's health professional if you're concerned that your child has high blood pressure.

If you have high blood pressure, making a few lifestyle changes can improve your heart health.

• Reduce salt, also called sodium. The American Heart Association recommends that healthy adults have no more than 2,300 milligrams (mg) of sodium a day. Ideally, most adults should limit salt to less than 1,500 mg a day. Check the amount of salt in processed foods, such as canned soups and frozen foods.
• Eat healthy foods. Choose fruits, vegetables, whole grains and low-fat dairy foods. Eat less saturated fat and total fat.
• Avoid or limit alcohol. Alcohol can raise blood pressure. If you choose to drink alcohol, do so in moderation. For healthy adults, that means up to one drink a day for women and up to two drinks a day for men.
• Don't smoke or use tobacco. If you need help quitting, ask your healthcare team about strategies that can help. Also try to avoid secondhand smoke.
• Keep a healthy weight. Having too much body weight is a risk factor for high blood pressure. Losing even just a few pounds can lower blood pressure. Ask your healthcare professional what a good weight is for you.
• Be physically active and exercise regularly. Staying active helps lower your blood pressure and manage your weight. The Department of Health and Human Services recommends that most healthy adults get at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week, or a combination of the two.
• Get good sleep. Poor sleep may increase the risk of high blood pressure and heart disease and other health conditions. Adults should aim for 7 to 9 hours daily.

If lifestyle changes do not successfully control your blood pressure, your healthcare professional may suggest one or more medicines. Together, you and your healthcare team can discuss the best treatment options for you.