A blood pressure test measures the pressure in your arteries as your heart pumps. You might have a blood pressure test as a part of a routine doctor's appointment or as a screening for high blood pressure (hypertension). Some people use a blood pressure test at home to better track their heart health.

A blood pressure test is a routine part of most doctor appointments. Blood pressure screening is an important part of your general health. Find out when you should have a blood pressure test.

• People age 18 and older with normal blood pressure and no heart disease risk factors should have a blood pressure test at least once every two to five 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 chronic health conditions, such as high or low blood pressure or heart disease, may need to have blood pressure tests more often.

Your doctor may also suggest checking your blood pressure at home. Automated home blood pressure monitors are available and easy to use. Some can be connected to your computer or cellphone, making it easy to transfer the information to an online medical record. Ask your doctor if this is an option for you.

It's a good idea to keep a blood pressure log at home and have your doctor check your monitor once a year to make sure you are getting accurate readings.

Home blood pressure monitoring isn't a substitute for visits to your doctor.

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

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

• Do not smoke, exercise or drink caffeinated beverages for 30 minutes to an hour before the test. Such activities increase your heart rate and blood pressure.
• Consider wearing a short-sleeved shirt so that the blood pressure cuff can be placed more easily around your arm.
• Relax in a chair for at least five minutes before the test.
• Tell your doctor about the medications you take. Some drugs may affect your blood pressure.

During the procedure

Usually, a nurse or technician takes your blood pressure while you are seated in a chair with your feet flat on the floor.

You rest your arm on a table at the level of your heart.

The blood pressure cuff is wrapped around the top part of your arm. The bottom of the cuff is just above your elbow. It's important that the cuff fits. Readings can vary if the cuff is too big or too small.

• For a manual blood pressure measurement, the nurse or technician places a stethoscope over the major artery in your upper arm (brachial artery) to listen to blood flow.
• The cuff is inflated with a small hand pump.
• As the cuff inflates, it squeezes your arm. Blood flow through the artery stops for a moment.
• The nurse or technician opens a valve on the hand pump to slowly release the air in the cuff and restore blood flow. He or she continues to listen to blood flow and pulse and records your blood pressure.

Some blood pressure cuffs automatically inflate and measure your pulse. In this case, a stethoscope is not needed.

It takes about one minute to get a blood pressure measurement.

After the procedure

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

Your doctor, nurse or technician can tell you your blood pressure results immediately after the test.

Blood pressure is measured in millimeters of mercury (mm Hg). A blood pressure measurement has two numbers:

• The top number (systolic) is the pressure of the blood flow when your heart muscle contracts, pumping blood.
• The bottom number (diastolic) is the pressure measured between heartbeats.

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

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

• Reduce salt (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. Remember to check salt content 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.
• Limit alcohol. Alcohol can raise your 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.
• If you smoke, quit. You should also try to avoid secondhand smoke.
• Lose weight. If you're overweight, losing even 5 pounds (2.2 kilograms) can lower your blood pressure.
• Exercise regularly. Staying active helps lower your blood pressure and manage your weight. Most healthy adults should aim for at least 150 minutes of moderate aerobic activity or 75 minutes of vigorous aerobic activity a week, or a combination of the two.

If lifestyle changes do not successfully manage your blood pressure, your doctor may recommend medication. If you have low blood pressure, your symptoms will depend on the cause. Together, you and your doctor can discuss the best treatment for you.