Blood pressure test
Blood pressure test
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 routine doctor's appointment or as a screening for high blood pressure (hypertension). Many people, such as those with high blood pressure, do their own blood pressure tests at home so they can better track their health.
You may have frequent blood pressure tests if you've been diagnosed with prehypertension, high blood pressure (hypertension) or low blood pressure (hypotension).
Why it's done
Having a blood pressure test is a routine part of most medical appointments.
Your doctor may order separate appointments for repeat blood pressure tests to check for ongoing health conditions, including prehypertension, high blood pressure (hypertension), low blood pressure (hypotension), heart disease or other conditions.
You should have a blood pressure test performed at least once every two years to screen for high blood pressure as a risk factor for heart disease and stroke, starting at age 18. Your doctor may recommend screening at a younger age if there are additional risk factors for developing heart disease, such as being overweight or having a family history of high blood pressure or heart disease. If you've already been diagnosed with high or low blood pressure, you should have blood pressure tests more frequently.
Even if your doctor doesn't think you have high or low blood pressure as an ongoing condition, your blood pressure is important information for your doctor. It can provide information about your general health.
Your doctor may recommend that, in addition to regular blood pressure tests at a doctor's office, you perform blood pressure tests at home. There are automated home blood pressure monitors that are easy to use.
Having a blood pressure test doesn't have any risks to your health. The squeezing of an inflated blood pressure cuff on your arm may be uncomfortable, but it should last only a few seconds.
How you prepare
No special preparations are needed for a blood pressure test. You might want to wear a short-sleeved shirt to your appointment so the nurse or technician doing your blood pressure test has easy access to your left arm to perform the test. However, if the main reason for your doctor's appointment is to check for or monitor high blood pressure, you should use the toilet before your test to empty your bladder, and avoid drinking caffeinated beverages, eating and smoking for one hour before your test.
Because some medications — such as over-the-counter cold medicines, antidepressants, birth control pills and others — can affect your blood pressure, it might be a good idea to take a list of medications and supplements you use to your doctor's appointment. Don't stop taking any prescription medications that you think may affect your blood pressure without your doctor's advice.
What you can expect
During the procedure
The test is performed best while you're seated in a chair in the examining room. Your arm should be supported, resting on a table at heart level, both feet flat on the floor and back supported by the chair.
Your nurse or technician will wrap an inflatable cuff around the top part of your arm so that the bottom of the cuff is just above your elbow. The cuff is attached to a dial, digital display or a device that looks similar to a thermometer. This equipment is called a sphygmomanometer (sfig-mo-muh-NOM-uh-tur).
Throughout the test, you should try not to talk or move your arm. The nurse or technician will feel the pulse at your wrist and then take a reading with the sphygmomanometer, checking for when the pulse is felt as the air deflates from the cuff. This is so he or she can figure out how much air to pump into the cuff to accurately measure your blood pressure.
Once a pulse from an artery is found and the stethoscope is positioned above the elbow, so the nurse or technician will hear the blood flow, he or she will begin inflating the cuff with a small hand pump. The nurse or technician will inflate the cuff to momentarily stop the blood flow through the artery in your arm.
Then the nurse or technician will open a valve on the hand pump to slowly release the air in the cuff. He or she will continue to listen to your pulse with a stethoscope to record your systolic and diastolic blood pressure. Systolic pressure — the top number of your blood pressure reading — is the pressure of the blood flow when your heart muscle contracts. Diastolic pressure — the bottom number of your blood pressure reading — is the pressure measured between heartbeats. Blood pressure is measured in millimeters of mercury, which is abbreviated mm Hg.
It's also possible your blood pressure will be measured using a machine that automatically measures your pulse to figure out your systolic and diastolic blood pressure. If this is the case, it's not necessary for the nurse or technician to search for your pulse with a stethoscope.
Whether your blood pressure is measured manually or with an automatic machine, it takes about a minute to complete a single blood pressure measurement.
After the procedure
If your doctor thinks you may have high or low blood pressure and is trying to decide the best treatment options for you, you may need to have two or three follow-up appointments to have your blood pressure checked. This is because your blood pressure can vary from day to day. Your doctor will look at the results of each of your blood pressure tests to see if you need treatment. You may be instructed to take several blood pressure readings at home.
Tracking your blood pressure readings
You can learn your blood pressure measurement as soon as your test is over. A blood pressure reading, given in millimeters of mercury (mm Hg), has two numbers. The first, or upper, number measures the pressure in your arteries when your heart beats (systolic pressure). The second, or lower, number measures the pressure in your arteries between beats (diastolic pressure).
Here's a look at the four blood pressure categories and what they mean. If your readings fall into two different categories, your correct blood pressure category is the higher one.
*Ranges may be lower for children and teenagers. Talk to your child's doctor if you think your child might have high blood pressure.
Prehypertension and stages 1 and 2 hypertension
If lifestyle changes alone aren't enough, or if you have stage 2 hypertension, your doctor may recommend medications to help lower your blood pressure. Your doctor will discuss which medication options might work best for you.
Low blood pressure
Last Updated: 2010-04-08
© 1998-2013 Mayo Foundation for Medical Education and Research (MFMER). All rights reserved. A single copy of these materials may be reprinted for noncommercial personal use only. "Mayo," "Mayo Clinic," "MayoClinic.com," "Mayo Clinic Health Information," "Reliable information for a healthier life" and the triple-shield Mayo logo are trademarks of Mayo Foundation for Medical Education and Research.
Terms and conditions of use