When was the last time you visited a doctor’s office? Whether it was last month or a few years ago, you almost assuredly experienced the same routine: 1) you were weighed, 2) your blood pressure was measured and 3) your temperature was monitored. Your weight may have been off by a bit because you were probably wearing your shoes and clothes. Men probably have wallets in their back pocket along with a cell phone, but that’s not a big deal. Temperature readings are generally accurate. On the other hand, blood pressure measurement mistakes are common! No one seems to care, even though this key biological metric is really important.
Who’s Measuring Your Blood Pressure?
Blood pressure is an important risk factor for cardiovascular disease. In recent years the recommended threshold for treating hypertension has been lowered. Health professionals are expected to help people get their systolic blood pressure below 130 and their diastolic blood pressure readings below 80. So-called normal blood pressure is 120/80 or below.
There was a time when nurses and doctors measured blood pressure. They still do…occasionally. But if you go to a typical clinic these days the chances are good that the metrics mentioned above will be taken by a lower-paid technician. It has been our experience that these individuals have not been adequately trained. Blood pressure measurement mistakes are common!
Measuring blood pressure is not as simple as it seems. Doctors and nurses sometimes make errors. The technicians we have encountered in recent years rarely get the entire process correct. And that is at top-notch medical facilities where administrators should know better.
Cuff Size: One of the Most Common Blood Pressure Measurement Mistakes!
Researchers from Johns Hopkins University reported on a fascinating randomized crossover trial to determine the “Effects of Cuff Size on the Accuracy of Blood Pressure Readings” (JAMA Internal Medicine, August 7, 2023). The authors examined the effects of using a single standard-size blood pressure cuff to measure blood pressure in 195 adults with a wide range of arm sizes.
People with thin arms ended up with a reading lower than their actual blood pressure. In contrast, those with large arms had blood pressure readings substantially higher when measured with the standard cuff compared to a large cuff.
If people who needed an extra-large cuff were measured with a regular-sized cuff, the average blood pressure reading was 144/88. When these same individuals were measured with an appropriately-sized cuff, the readings averaged 125/79. The wrong-size blood pressure cuff for such individuals could lead to unnecessary treatment and more adverse drug reactions.
Please hit your internal pause button. When was the last time a technician (or a doctor or nurse for that matter) actually measured the circumference of your arm? I would bet it would be rare to never.
Everyone is in a hurry these days and most exam rooms do not have a way to measure arm size. More important, most exam rooms do not come equipped with various-sized blood pressure cuffs.
The Authors of This Study Introduce the Problem:
“Hypertension is the leading cause of cardiovascular disease worldwide. Accurate measurement of blood pressure (BP) is used to screen for hypertension and to diagnose and treat hypertension. Although there are several preparatory and positioning steps required for accurate BP measurement, individualized selection of appropriate cuff size is often overlooked, despite clinical practice guidelines.”
In other words, doctors have been told exactly what they are supposed to do prior to measuring a patient’s blood pressure. Many of those steps are ignored, especially the part about selecting “appropriate cuff size.”
Here is the “meaning” of this study according to the researchers:
“Using a regular BP cuff size for all individuals regardless of arm size resulted in strikingly inaccurate BP readings with an automated device; a renewed emphasis on individualized BP cuff selection is warranted, particularly in individuals with larger arm sizes.”
Let’s be really honest for a moment. A lot of Americans now come with “larger arm sizes.” We are a nation that is largely overweight. If a technician uses a “standard” cuff size on someone with a larger arm circumference, it is likely that the BP reading will higher than it actually should be. That could lead to an extra blood pressure medicine and that could lead to additional adverse drug reactions.
The SPRINT Trial vs. Office Readings:
Research published in JAMA Internal Medicine (Oct. 12, 2020) compared office blood pressure measurements to the careful readings obtained in the SPRINT research trial. There were over 3,000 patients whose data in these two different settings were compared.
To be clear, these patients were participating in this very carefully supervised research program. The investigators followed techniques for taking blood pressure that followed strict guidelines established by professional societies. The same patients had their blood pressure measured during routine doctor visits.
There was surprising variability between the numbers obtained in the office and those in the study. Many of the participants had higher blood pressure readings in the routine office visits compared to the research setting. The range of discrepancy was substantial. These higher BP readings could lead to the misdiagnosis of hypertension and the prescribing of unnecessary drugs.
Blood Pressure Measurement Mistakes:
The authors of the study offer this explanation for the differences in readings:
“Our results are generally consistent with prior studies that have demonstrated that BPs measured using proper technique are typically 5 to 15 mm Hg [mercury] lower than the corresponding BPs measured in the routine clinical practice settings. Improper BP measurement technique is likely the underlying cause of higher BPs in routine clinical practice compared with trial measurements. Nearly all of the protocol deviations in routine practice (eg, lack of rest period prior to readings, talking during measurement, and arm not supported) are associated with overestimation of BP.”
A Commentary on Blood Pressure Measurement Mistakes:
A commentary in the same issue of the JAMA Internal Medicine (October 12, 2020) noted that routine blood pressure measurements in the office setting don’t often follow established guidelines. People are rarely given 5 minutes of quiet time before their blood pressure is measured three different times.
The cuff size is almost never matched to the size of the patient’s arm and people may not be positioned with their feet on the floor, their back supported, and their arms supported at heart level.
The researchers suggest that blood pressure measurement mistakes might have contributed to the problem. The authors emphasize that proper blood pressure measurement technique is crucial.
The authors note:
“Blood pressure measurement in the office setting has been the primary method used for managing hypertension. These data underscore what has been reported in the literature for decades—routine office BP and research-quality office BP are different measures—and highlight the major gap between clinical practice and research studies in the management of hypertension.”
We now know that there are lots of blood pressure measurement mistakes made in the doctor’s office or clinic.
Readers Share Their Stories About Blood Pressure Measurement Mistakes:
We have heard from many readers who complain about pain when the BP cuff is inflated. Here is Gigi’s story:
“I have so much pain in my arm from a tight cuff when they check blood pressure. The nurse tells me to lower my arm, and rest my hand in my lap. This is wrong. If I try to place it at heart level, I am reprimanded.
“I can go in perfectly normal, and my BP will go up to 190 because they continually keep taking it the wrong way. Last week, the nurse took it 8 times in a row until I refused to let her touch me. My BP goes up as soon a the cuff begins to tighten. It’s like a panic attack, and nothing helps.”
Gayle has also had problems with automated blood pressure equipment:
“The new auto BP cuffs at the doctor’s office hurt like a *#*, and suddenly I have high blood pressure and am put on a medication to treat it. The drug makes me cough– not acceptable!
“I quit that med, and when next at the doctor’s office months later, insisted on manual reading. Big surprise, my BP was back to its usual 116/70. Gee I guess pain does raise your BP!”
Here is why waiting several minutes prior to BP reading is essential! Mary shares this story:
“My husband was at the doctor’s office and his first BP reading was 158. The doctor was very concerned but my husband said wait. After they had talked, my husband asked her to do another reading. It was 101, this was 15 minutes later! He dropped 57 points in 15 minutes.”
Preventing Blood Pressure Measurement Mistakes:
We have written extensively about how blood pressure measurements should be taken. Here is a link to an article with practical tips:
Seven Mistakes to Avoid When Measuring Blood Pressure!
Do you avoid mistakes when measuring blood pressure? We are constantly amazed at how many technicians incorrectly take blood pressure readings. Here are tips to help you eliminate errors.
You may also find this article of value:
What’s the Best Way to Measure Blood Pressure?
What’s better, blood pressure readings at the doctor’s office or at home? A new study will surprise many health professionals. The results should change attitudes!
Our eGuide to Blood Pressure Treatment provides additional insights on how to avoid blood pressure measurement mistakes. It also offers nondrug options for helping to control high blood pressure. Here is a link.
Final Words and Choosing the Right Size BP Cuff:
Before you let someone measure your blood pressure at a clinic or doctor’s office, ask that person to measure the circumference of your arm. That is especially important if you are either under or overweight! If they look at you with a blank stare, ask them if they have a cuff to accommodate your arm size.
Here are some guidelines to help you make sure you get the right size blood pressure cuff (American Journal of Hypertension, Nov. 2022):
Mid-arm circumference:
- Less than 26 cm (1o.2 inches) = Small Adult Size Cuff
- 26-34 cm (10.2 to 13.4 inches) = Regular Adult Size Cuff
- 34-44 cm (13.4 to 17.3 inches) = Large Adult Size Cuff
- More than 44 cm (17.3 inches) = Extra Large Adult Size Cuff
Please share your own experience with blood pressure measurement in the comment section below. If you think this article could help a friend or family member, please send it along.
