However, measuring blood pressure accurately can be difficult. In fact, if you have your blood pressure taken at the hospital, there’s a good chance that the readings you get will not reflect your actual blood pressure. Raj Padwal, a professor of medicine at the University of Alberta in Canada who runs a hypertension clinic, says he doesn’t typically ask patients for their blood pressure readings in the clinic. “Because 50 percent of the time, the measurements are inaccurate.”
There are several reasons why in-office measurements can be misleading. But the good news is that there are easy and relatively inexpensive ways to accurately know your blood pressure from the comfort of your home.
Problems with blood pressure testing in the doctor’s office
Blood pressure is very sensitive and changes from moment to moment. “It’s affected by a variety of factors, including your emotional state, mental health, physical activity, ambient temperature, medications, whether you’ve eaten, and whether you’ve slept well,” says Padwal.
This vital sign is measured in two numbers: Systolic blood pressure. The top number represents the pressure exerted on the arteries when the heart contracts. Diastolic blood pressure is the lowest number and represents the pressure exerted on the arteries when the heart is at rest.
To get an accurate blood pressure reading, you need to follow very specific steps, such as placing your feet flat on the floor, your back on a sturdy chair, and your arms on a flat surface. Also, the cuff should be placed directly on your skin (not over your shirt) at the same level as your heart. Also, empty your bladder and sit quietly for a few minutes before taking the measurement. However, many of these requirements are not always met in clinics, and staff may be too busy to guide you to the appropriate location.
Additionally, clinics may experience problems with their equipment. You may think that a blood pressure monitor is more accurate than your home blood pressure monitor, but this is often not the case. Analog devices that use cuffs or pressure gauges need to be calibrated every few months, but this rarely happens, said Jordana Cohen, associate professor of medicine and epidemiology at the Perelman School of Medicine at the University of Pennsylvania. Digital blood pressure monitors, which are also used in medical settings, are more reliable.but Only a small portion of them have been independently verified for accuracy, a process called validation. Also, your doctor’s office may not have the correct cuff size for your arm, and a cuff that is too large or too small may give inaccurate measurements.
Some people experience something called. white coat hypertensionIf your blood pressure increases in the exam room, perhaps due to the stress of the exam.others have masked hypertension, blood pressure decreases in the doctor’s office, probably because people who have a lot of stress in their daily lives feel calmer in the doctor’s office. Although the true prevalence of these conditions is unclear, it is believed that 15 to 30 percent of people have white coat hypertension, and about 32 percent of people with normal office blood pressure measurements have masked hypertension.
All of this may explain why hospital blood pressure measurements vary so widely.a 2023 study evaluated data from over 500,000 people They found that between two consecutive doctor’s visits, a person’s systolic blood pressure readings changed by an average of 12 mmHg (the unit of measurement for blood pressure) in either direction.
It’s not just a small rounding error. When starting a new blood pressure drug, doctors typically expect the drug to lower blood pressure by less than 12 mm Hg, said study author Harlan Krumholz, a cardiologist and professor at Yale School of Medicine. To tell. This means that if doctors rely only on office measurements, they cannot be sure whether the drop in blood pressure is due to the effect of the drug or to something else entirely.
Krumholz says the only way to overcome this is to collect many measurements (as many as 20) and average them. Fortunately, experts say there’s an easy way to alleviate all these problems: home blood pressure monitoring.
Why home blood pressure monitoring works so well
If you want to measure at home, you can purchase a high-quality monitor with a cuff that fits around your arm. You can also prepare properly and follow the correct steps when sitting down. You can also take multiple measurements on different days and provide that data to your doctor.
Monitoring your blood pressure at home is especially valuable for people whose office blood pressure readings indicate high blood pressure, or for people who are at higher risk for heart disease due to pre-existing health conditions such as diabetes, Padwal said. . It’s also useful for tracking the effects of new drugs or adjusted doses, and for those who need to be careful during pregnancy, postpartum, and severe high blood pressure called pre-eclampsia.
And not only is home monitoring more accurate than office checks, some studies have found that actually helps control blood pressureThis is especially true during the first few months of using the monitor.
Sphygmomanometer selection
It is important to purchase an accurate home blood pressure monitor. Most manufacturers do not publish accuracy test results, but some medical groups create lists of devices that have been verified by independent experts. All the experts we spoke to recommended: American Medical Association List of American Blood Pressure Validated Devices Use this as a good starting point when purchasing a home monitor. Consumer Reports also rates BP monitors (though their ratings are behind a paywall).
There are two types of home blood pressure monitors: one that is worn on the upper arm and one that is worn on the wrist. Generally, experts (and CRs) recommend arm monitors. Arm monitors tend to be more accurate because there is less room for error in positioning.
However, it is important to use the correct arm cuff size to get accurate measurements. Some people with large arm circumference may not be able to find an arm monitor with the appropriate cuff size. In such cases, a wrist monitor is a good alternative.just need to take Take special care to place it correctly. In CR’s tests, none of the wrist monitors scored high enough to earn a recommendation, but several monitors still had very high accuracy scores.
Instead of purchasing your own blood pressure monitor, you may be wondering if using a blood pressure kiosk at your pharmacy is a good idea. But Padwal says very few public blood pressure kiosks have been verified by independent experts. Additionally, it may be difficult to follow guidelines for correctly measuring blood pressure if you’re in the middle of a crowded pharmacy.
Copyright 2024, Consumer Reports Inc.
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