Derek Burnett
Derek Burnett is a Contributing Writer at Bottom Line Personal, where he writes frequently on health and wellness. He is also a contributing editor with Reader’s Digest magazine.
If you’ve been diagnosed with hypertension, experts recommend that you get a home blood pressure monitor and keep track of your pressure on a regular basis. Home monitoring is not something to do out of idle curiosity or just when you’re not feeling well. Regular blood pressure readings are an important part of your overall blood-pressure management strategy. A study published in JAMA Network Open found that, among 2,500 hypertension patients, those who regularly took home readings were able to lower their systolic pressure (the “top number”) by an average of 17 mmHg and their diastolic pressure (the “bottom number”) by 6.4 mmHg on average.
Keeping track of your readings in a blood pressure log can alert you to fluctuations in your pressure that could be caused by over-the-counter medications or changes in health. And, as you watch your readings continue to drop, your log can be a source of motivation to keep up the lifestyle changes such as diet, exercise and improved sleep that are helping you manage your pressure.
Getting an accurate blood pressure reading is not difficult, but there are certain steps that must be followed to make sure you’re doing it correctly. Selecting the right device, timing your readings, and using the correct technique are all important.
There are literally hundreds of blood pressure monitors on the market these days. Some are very sophisticated, with extra bells and whistles that can log your readings and share them automatically with your healthcare provider, monitor for heartbeat irregularities, take your blood oxygen levels, interact with your smartphone, and more. Others are very streamlined, taking your blood pressure with the push of a single button. The American Heart Association (AHA) now recommends using devices that can log readings to be printed or shared electronically with your doctor. But there’s no reason to overspend on a device. In fact, the simplest devices are often the most accurate.
Don’t purchase a monitor with a wrist or finger cuff instead of an upper-arm cuff unless there’s a medical reason why you can’t use your upper arm (such as mastectomy with lymph-node dissection or dialysis). Wrist and finger monitors are generally significantly less accurate than arm monitors because the farther the cuff is away from the heart, the more difficult it is to get a good reading.
Steer clear of the public blood pressure monitors you see in kiosks in pharmacies or gyms. They’re unlikely to be calibrated properly, and their one-size-fits-all cuffs may not fit you right. Also avoid relying on smartphone apps that purport to take your blood pressure. That technology could improve in the future, but for now it’s not accurate enough to count on. Use an actual home monitor instead.
When you’re shopping for a monitor, visit the AHA-sponsored website validatebp.org, which lists all the monitors on the US market that have been rigorously tested for accuracy. Monitors will also have an FDA-approval stamp, but don’t mistake that for a quality seal. It merely means that the device has met the minimal requirements to be put on the market.
You need to make sure the cuff fits your arm properly. If you have an unusually large or small upper arm, you’ll need to pay particular attention to fit. A cuff that’s too small will give you a too-high reading, while a loose cuff will underestimate your blood pressure. Measure your arm’s circumference halfway between the elbow and shoulder. Compare the measurement to the cuff circumference listed in the device’s specifications. If that’s too difficult for you to do, ask your doctor to measure your arm and write down the recommended cuff size. Manufacturers do produce monitors for extra-large and extra-small arms. Validatebp.org lets you search available monitors in those categories that have undergone testing.
Once you’ve selected and purchased a device, take it with you to your doctor’s office and ask for help ensuring that it’s calibrated correctly and that the cuff is a good fit. Make a habit of bringing the device along to future appointments to make sure it’s maintaining its accuracy.
Take your blood pressure on whatever schedule your doctor recommends. Most physicians will ask you to take your blood pressure twice each day, once when you first get up (and before taking any blood pressure medications) and once just before bed (again, before taking meds if you normally take them at bedtime). Taking your pressure at the same times daily will give you a better baseline against which to measure any fluctuations or directional changes.
An hour before you take your blood pressure, stop consuming any caffeine or nicotine, and refrain from vigorous exercise, all of which can cause temporary spikes in pressure. A few minutes before your reading, go to the bathroom, since a full bladder can also throw off your result. Get into the chair where you’ll take your blood pressure about five minutes before you do the reading. You should be sitting peacefully in a quiet room without a lot of stimulation such as conversation or a blaring TV.
Position yourself in a chair with back support, feet on the floor and legs uncrossed, at a table that allows you to lay your arm out on it at the level of your heart. Don’t ever take your blood pressure with your arm dangling by your side or held up in the air, since those readings will almost certainly be invalid. Place the cuff on your bicep so that its lower edge sits about one inch above the bend in your elbow. Make sure your arm is bare, since placing the cuff over a sleeve can throw off the result. Don’t talk during the reading. Each time, take two readings, one with each arm. Log the higher of the two readings. That means that every morning you’ll take the pressure in your right and left arm, and every night at bedtime you’ll do the same. A small difference in readings between your two arms is not cause for concern, but if you consistently see a difference of 5 mmHg or more, tell your doctor. It could signal a cardiovascular problem that merits some attention.
