Why You Can Trust CNET 4 simple steps to choosing the best at-home blood pressure monitor
Not every blood pressure monitor is a good one. Here’s how to find the right one for you.
The American Heart Association recommends that people with hypertension measure their blood pressure at home.
If you have high blood pressure, getting an accurate reading can quite literally be a matter of life or death -- blood pressure isn't called a vital sign for nothing. You can trust your doctor to get accurate blood pressure readings during your visits, but what if you need to measure your own blood pressure at home?
That's when things can get a little more tricky. Blood pressure is one of hundreds of health-tracking measures that wellness and fitness tech companies have jumped on, and devices like this blood pressure cuff that doubles as a smartwatch are now the norm.
However, even the snazziest of devices may not be accurate, warns the American Heart Association. The AHA has developed guidelines regarding at-home blood pressure monitors, and it's a good idea to keep those -- as well as personal factors -- in mind when shopping for a personal blood pressure monitor.
1. Decide on a wrist or arm-based blood pressure monitor
If you're able to wear an arm-based blood pressure monitor, you should: When it comes to at-home monitoring, the AHA only recommends the use of upper-arm cuff oscillometric devices that have successfully passed validation protocols. (Oscillometric devices automatically detect and analyze pulse waves so you don't have to rely on someone to listen with a stethoscope.)
Wrist- and finger-based blood pressure monitors typically aren't as accurate, Yale Medicine cardiologist Erica S. Spatz, MD tells CNET.
However, there are some circumstances in which a wrist- or finger-based blood pressure monitor might be preferable to an arm-based monitor, such as if you have a disability that prevents you from affixing an arm-based monitor or if your arms are too large to fit in an arm cuff (more on that next).
The Qardio Arm wireless blood pressure monitor has passed British and Irish Hypertension Society validation protocols.
2. Measure your wrist or arm
A big part of getting an accurate blood pressure reading is using a blood pressure monitor that fits correctly. If your blood pressure monitor is too big or too small, you may receive an inaccurate measurement.
Even a device with all the possible bells and whistles won't work properly if it doesn't fit. Your at-home blood pressure monitor should compress your brachial artery (the main artery in your arm). "All too often, the fit of the blood pressure cuff is imperfect," Spatz says. "This can result in under- or overestimation of the blood pressure -- and many people may be misdiagnosed [with hypertension]."
If you're unsure about what size cuff you need even after measuring your arm, simply ask your doctor at your next appointment, advises cardiologist Jennifer Haythe, MD, co-director of Columbia Women's Heart Center. "Guidelines exist for how large a cuff one needs based on the length and circumference of your arm," she says.
Spatz offers a helpful step-by-step:
"The first step is to measure the circumference of the upper arm; use the middle of the upper arm around the bicep," Spatz says. "Take the circumference, in centimeters, and multiply it by 80% to get the right length and 40% to get the right width of the bladder cuff. The bladder of the cuff is the part that fills with air, not the extra length of Velcro."
If you have larger arms that are significantly wider near your shoulder than your elbow, you may also want to get a cone-shaped or "contour" cuff. Research finds that using standard cylindrical cuffs can produce inaccurate measurements because the variation in arm size causes the bladder to expand irregularly.
If an extra-large cuff does not fit, the AHA recommends measuring your blood pressure at the wrist. Although measuring at the wrist tends to be less accurate than the upper arm, a meta-analysis shows it tends to be better than the forearm or finger.
"Arms come in all shapes and sizes, and people with obesity should not feel bad about having a difficult time finding the right cuff size," Spatz says. "It is really unfortunate that the cuffs have not evolved to match different arm sizes."
An example of a contour-style blood pressure cuff.
If you do end up needing a wrist-based blood pressure monitor, again, check that it's been validated. And then follow these instructions, with one change: "Rest your elbow on a table and bring the cuff to the level of your heart, as when reciting the pledge of allegiance," says Spatz. Keep your arm relaxed and your hand resting against your chest until the reading is complete.
3. Write down the top features you need in a blood pressure monitor
Other than a blood pressure reading, what else do you need out of your at-home blood pressure monitor? For example, a built-in arrhythmia (irregular heartbeat) detector could be beneficial for people who have tachycardia (fast heartbeat), bradycardia (slow heartbeat) or other types of atrial fibrillation.
Some things to ask yourself before settling on a blood pressure monitor include:
- Will I share this blood pressure monitor with other people? If so, look for one that allows for multiple accounts.
- Do I want or need my readings to transfer to my phone? If so, look for one with Bluetooth connectivity.
- Do I need to send these readings to my doctor? If so, look for one that offers some sort of communication feature, such as the ability to email readings directly from an app.
- How long do I need to store my readings for? If you'll need to look at long-term trends, make sure to look for a monitor that stores your measurements over time.
Other factors to consider include the display (brightness, text size, and colors), portability, battery life, type of battery and app interface of the companion app to the product you're using. The last one is particularly important, because if you can't figure out how to navigate the app, you won't be able to see your blood pressure readings, export the data, or look at trends to inform your health decisions.
4. Check for clinical validation
After you have your measurements on hand and you know what features you need in your blood pressure monitor, you're almost ready to buy! Any time you're in the market for a health tech device that monitors vital signs, make sure to check for clinical validation. This means a product has undergone clinical testing and has satisfied the requirements of the AHA.
The AHA recognizes validation protocols from the following organizations: the German Hypertension League, the Association for the Advancement of Medical Instrumentation, the European Society of Hypertension and the British Hypertension Society -- with the BHS protocol's being the most complex and thorough. A new international universal validation protocol is being developed that may become the new standard, so keep an eye out for that.
The Qardio Arm is a clinically validated at-home blood pressure monitor.
Many blood pressure monitors on the market haven't been validated. So before you buy one, check to make sure it has. You can find a list of validated monitors -- like these from Qardio and Omron -- on the British and Irish Hypertension Society and Dabl Educational Trust websites.
If you're pregnant, have atrial fibrillation or have a large arm circumference -- or you'll be using the monitor for a child -- make sure the device has been validated for use in those specific populations, too.
5. Consider your budget
At-home blood pressure monitors can cost as little as $30 to more than $100. With something like blood pressure, you'll have to figure out the best balance between staying in your budget and choosing a product that best supports your health.
To get started, you can browse our list of the best at-home blood pressure monitors, which includes budget options and more luxurious, high-tech devices.
