The People's Perspective on Medicine

Can You Trust Wrist Blood Pressure Monitors?

Blood pressure measurement is far more complex than most people realize. Wrist monitors may seem convenient but Italian researchers found big problems.

People with elevated blood pressure are often encouraged to monitor it at home. That way they can tell how their blood pressure responds to a variety of conditions throughout the day.

Home blood pressure monitors have become sophisticated, easy to use and portable. However, researchers have wondered about the accuracy of these electronic blood pressure monitors.

What the Italian Researchers Uncovered:

Italian scientists did a study of 721 hypertensive patients and found that wrist blood pressure monitors are less accurate than those that use a cuff higher on the arm (Hypertension, online Aug. 22, 2016). 620 of the people in the study had a significant discrepancy between blood pressure measurements. It’s not that the wrist monitors themselves are inaccurate or flawed. The problem appears to be primarily with the user.

Correct Placement of the Arm is Crucial:

For accurate measurements blood pressure monitors require that the arm and the wrist be positioned at heart level, and people often don’t know about this or aren’t able to do it. Failure to have the wrist at the correct position can lead to a falsely elevated reading and might result in people being treated unnecessarily.

Here is what the researchers noted:

“Upper-arm automatic devices gave fresh impetus to home self-measurement because of their user friendliness, the only conditions to be respected being adequate cuff dimensions and correct positioning of the cuff on the patient’s arm.

“For reasons of market penetration and following a general tendency to miniaturization, many wrist devices recently appeared on the market having the advantage of being smaller and easier to fit than upper-arm monitors, and today wrist devices are used by a large portion of people who measure their BP at home. However, in spite of technical improvement, their reliability in real-life conditions is not unanimously accepted.”

Here is what the researchers found  about blood pressure monitors:

“The main finding of our study is that the relationship between BP measured at the upper-arm and at the wrist varied according to whether BP measurements were made in the office under a doctor’s supervision or at home in a real-life situation. When BP was taken in the office, the values measured at the wrist were, as shown by others, slightly lower than those measured at the upper-arm. In contrast, when BP was self-measured at home by the study participants, higher BP values were obtained at the wrist than at the arm.”

The Key Findings About Blood Pressure Monitors:

When people take their blood pressure with a wrist monitor there is a significant likelihood that they will not have their wrist at heart level. Chances are good that their arm will be resting on an arm of a chair or in their lap. This will falsely elevate their blood pressure by as much as 10 or more points. That is enough to lead to a false diagnosis of hypertension.

What we have observed at a major teaching hospital:

Duke University Hospital likes to pride itself on exceptional care but we have observed that one of the most fundamental measurements that the hospital requires (blood pressure) is often done incorrectly. At virtually every outpatient visit an aide weighs patients, takes their temperature and measures their blood pressure. Rarely is there any effort to follow the American Heart Association’s guidelines to have the arm supported at heart level.

We wonder how many other hospitals, clinics and doctors’ offices strictly follow the AHA guidelines.

Blood Pressure Management:

If you would like to learn precisely how to take your blood pressure correctly, you may wish to consult our Guide to Blood Pressure Treatment. We have recommendations on how to get an accurate reading and a variety of strategies to manage blood pressure with and without medication.

Here is one tip that you should always implement. NEVER talk when you are having your blood pressure taken. Talking can falsely elevate your numbers to a surprising degree. We offer a number of Dos and Dont’s of Managing Blood Pressure in our Guide.

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About the Author
Joe Graedon is a pharmacologist who has dedicated his career to making drug information understandable to consumers. His best-selling book, The People’s Pharmacy, was published in 1976 and led to a syndicated newspaper column, syndicated public radio show and web site. In 2006, Long Island University awarded him an honorary doctorate as “one of the country's leading drug experts for the consumer.” .
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It’s not very informative when you get so many different experiences and ways of monitoring BP….and when a persons arm is so large and bruises easily what do you do?? Many ppl in nursing homes are fragile and they are large so how can you get an accurate reading when the cuff on the arm is so painful which to me would cause a false reading??!

I have been caring for my elderly Mother for the last 2 years. She has high blood pressure so I monitor it daily. I have both the wrist and arm monitors. I take the readings according to the guidelines, and I have even purchased 2 arm and 2 wrist monitors and keep the batteries new. The wrist monitors always record an average of 10-20 points LOWER than the arm monitors. Her heart rate is always the same on either machine. Yet when I google information about this everything says the wrist monitors record higher readings ?

The wrist BP monitors are significantly higher than the traditional arm band. Opticians & dental offices are using wrist bands. Why is taking BP their function? The doctors office uses the traditional arm band. The sleeve should be rolled up & the arm rested on a table or desk. Nurses have taken BP t over my sleeve , though I cautioned not to do it that way. They say it makes no difference.

Some nurses hold my arm at the elbow, though my arm is not relaxed, I am still constricting it more than if resting on the table. The office does not even have a desk for patients to rest their arm as it was always done in the past. Wrist bands might put many people on BP meds So folks take you own, especially if high. Remember ,potatoes k beets, maybe garlic will bring it down. They say oatmeal will lower cholesterol and High BP … Also 30 minutes of exercise works for many people. Does exercise raise your blood pressure. Salute to the Italians.

I recently had my blood pressure taken at my dentists office with a wrist monitor. The reading was 198/94. I have tendons on both wrists which I believe affects the readings. Could this be true, let me know.

I have used two different arm cuff blood pressure monitors, and the readings have been sky high! And all over the place. On top of that, the cuff squeezes my arm so tightly that I have bruises. I take 3 meds that can cause high blood pressure so I didn’t question the readings. When I spoke with my doctor, he suggested we rule out the meds before issuing blood pressure med. I bought a third blood pressure monitor … a wrist monitor. It will not only tell you how to position it, it shows pictures & won’t start until my wrist is level with my heart. Surprise, surprise! All the readings on the wrist monitor have been normal and consistent. Unlike what most articles say, it doesn’t seem to raise my readings. I also agree that most nurses do not take blood pressure readings correctly. My arm cuff has never been at heart level, and I’m 67!

Thank you. Very helpful and manage to get a much more accurate reading once I supported my wrist at heart level.

I agree completely! They put me in an exam room & the nurse comes in immediately to take my BP. I told her to wait at least 10 minutes because I have “white coat hypertension”.

She takes it anyway and then the Dr put me on BP medication because it was elevated:) now sometimes my BP is like 75/55 & I called Dr and she said take my BP before I take my medication and if it’s low or normal, don’t take BP medication. You can’t win :)

I checked my BP with a wrist monitor and averaged the readings as recommended – came out about 135.
Visited surgery for full check, and their readings averaged 160.
Assumed wrist monitor might be faulty as I was following the instructions that came with it.
This happened again at the next check-up; so I changed the monitor for a different brand.
And each year since the reading at the surgery can be as much as 20 points higher than what I get with the wrist monitor.

My doc doesn’t follow these guidelines either, so I ask him whether I should be at rest for a few minutes first, etc. His response is that it is also important to see where you’re blood pressure is during normal daily routines when you are moving about, possibly stressed a little at work, dealing with the kids and so on (or sitting in a 60 degree waiting room for an hour, then taking BP instantly when I sit down with him).

My BP was extremely high (160/100) at the doctor’s office. The nurse took my BP sitting and then standing (both done properly), with no change. I argued that my BP is normal at home. After two visits, they finally had me bring in my machine. They took my BP with my machine and theirs. Both registered the same high BP. Luckily, my machine records my BP, which I take almost daily at home. Looking over the past recorded BP numbers, the doctor agreed I was okay and didn’t need to take medication, chalking it up to White Coat syndrome. Interestingly, my BP is high at my internist’s office, but not at the dentist or allergist’s office.

How can doctors prescribe medication based on a single office visit? A few years earlier I took BP medication for a short while. One pill was enough to drop my BP immediately . After a week, my balance was affected, and it has never been the same.

I’m baffled by the article and warning about where the arm should be when using a wrist monitor. My monitor will not read unless my arm is at the proper level. If I left it on the arm of the chair, it would just ignore me.

I had the same experience this morning when I went to the doctor’s office. For the last 10 years, BP readings in the doctors office have been high. They used to check BP with the old manual cuff and now most of them use the machines. So I started checking mine with the home monitors, both wrist and cuff and readings were much lower well within normal.

I was put back on blood pressure medication after a doctor visit earlier this year when it was sky high in the office. I brought my wrist and arm monitor in for them to see my readings. So the nurse decided to check mine with the manual cuff and my BP was 115/80. The doctor comes in and uses their machine and it was 171/90. So I checked again using my wrist cuff and it was even higher.

At that point, he determined that it was being in their office that was pushing my BP up and then told me that they would keep me far away from them. He was joking of course, but was serious too. At least he had a good sense of humor about it and admitted said he thinks I have labile hypertension. I asked him why there was such a discrepancy between the manual cuff and the machine.

He thinks the machines are more accurate because when the manual cuff isn’t inflated enough, the higher numbers can be missed. Interesting to say the least. I think more doctors are starting to accept home readings because of this “white coat hypertension” phenomenon.

I would offer one more thought for the wrist monitor. Placement of the monitor is most important, but my first objective is fresh batteries. I try to remove the batteries after each use, and leave them in the box with the monitor until next time. I don’t know what the life expectancy of those little batteries is, but my life might depend on the reading.

This is an interesting topic. I am an RN – Retired, and find few medical personnel take B/P’s correctly. I insist on resting my arm at heart level on a desk or counter, and I will not converse while attempting to get a reading. Feet on floor; resting 5 min prior to B/P being taken; empty bladder; no eating one hour prior; no talking during reading — all of these important, as is using the appropriate size cuff!

I have fibromyalgia and blood pressure cuffs on my upper arms is extremely painful. I use the wrist cuff, which also hurts but not as bad. When I have been hospitalized, they use the cuff on my ankle which is the most comfortable for me.

Duke is not alone in improper procedure. I use WFBU healthcare. NEVER, have I been allowed to sit with both feet on the floor for five minutes o my arm elevated to heart level.

At my last physical, just a month ago, the nurse was inflating the cuff seconds after I sat down. When I commented on it, she said, “It’s not like you have been out running!”

Now I know what to ask my nurse to do when taking my blood pressure. Most of the time, my arm is supported by the nurse, but not at heart level. The rest of the time there was no support and I held my arm out at an angle. This varies among doctor’s offices. It will be interesting to see if the readings change at my next visit. Thank you for this information.

Several thoughts: when my BP is taken in my upper arm, the pain is intense and the reading is falsely high. In addition, many health care providers (docs, nurses, etc.) don’t comply with the need to keep the arm at heart height and also ask questions while taking my BP.

It’s ridiculous that I have to remind them of the proper way to do it (talking raises it, ‘arguing’ with them raises it, pain raises it) and so it’s been a long time since I have had a normal BP reading in a health care setting. Yet when I take it at home, with the cuff between the elbow and wrist (per an old doc’s recommendation) I invariably have a normal reading.

Sometimes, people cannot wrap their upper arm with a traditional blood pressure cuff and get it tight enough to give a decent reading. I’m betting that is one reason people have gone with the wrist cuff.

My last visit, the technician tried to take my BP with my arm at rest at my side. I had to insist on moving the chair so that I could rest my arm on the counter. And chairs that let my feet touch the floor are not common either (I’m 5’2″).

My doctor takes my BP herself, and she supports my arm at the correct level — BUT this is with me sitting on the end of the exam table with my legs dangling, which I have read will also elevate BP reading above that obtained when feet are resting on the floor.

Some automated BP monitors at pharmacies have adjustments to accommodate various torso heights, but most do not, so this is another potential source of error for patients relying on those machines for monitoring.

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