(Credit: Andrew Gebhart)
Smartwatches and wearables have made a lot of strides in the area of health monitoring in recent years. Sleep apnea detection and the ability to take an ECG on your wrist are now somewhat common features. A category that once lagged far behind chest straps in accuracy can now precisely measure heart rate during exercise and calculate running form metrics. Blood pressure measuring looks to be the next step on the horizon.
Samsung recently added the ability to measure your blood pressure to its line of Galaxy smartwatches in the US. After an initial calibration period with a separate cuff, you can use the Galaxy Watch can take a blood pressure reading. I tried it on the Galaxy Watch 8, and have previously tested similar features on the Whoop MG and recent Apple Watches, including the Series 11.
While valuable in theory, Samsung's blood pressure feature isn't something I'll use regularly after my week of testing. Because of logistical limitations, I’d argue that its current implementation isn't useful for everyday consumers just yet.
You Still Need a Dedicated Blood Pressure Monitor
Blood pressure monitoring has been available in Samsung watches overseas since 2020, but is just now launching in the US due to various regulations. Note that the feature hasn’t actually gained FDA approval. As such, Samsung has been sure to clarify that the feature is intended solely as a wellness reference, not to diagnose or prevent high blood pressure.
When announcing blood pressure monitoring, Samsung highlighted its two most recent smartwatches, the Galaxy Watch 8 and Watch 8 Classic, but the feature is rolling out to older models, dating back to the Galaxy Watch 4.
Before you go any further, know that you need a separate blood pressure cuff to even take a reading on the Galaxy Watch. Additionally, your watch will need to be paired with a Samsung phone running Android 12 or later for the feature to work. If you’re using your watch with another Android phone, you’re out of luck.
To get started, you need to download the Samsung Health Monitor app on your phone if you don’t already have it. Open the app, and you may see a prompt to start blood pressure calibration. Scroll over to the appropriate tab if not.
The app will then walk you through the calibration process, during which you'll use a third-party blood pressure cuff to take a series of readings. The app tells you to avoid alcohol, bathing, caffeine, exercise, and nicotine for at least 30 minutes before these calibration readings.
Once you’re set, you’ll be prompted to find a comfortable chair where you can rest your arm around the level of your heart, and then take a reading on your cuff. Be ready to hit start on your cuff at Samsung’s prompt, as the watch will be taking a reading at the same time. Once the watch's reading is complete, enter your cuff results in the app, and you’ll then be asked to repeat this process two more times.
After calibration, you can take subsequent readings by opening the Health Monitor app on your watch, though Samsung will prompt you to recalibrate every 28 days. The app also advises taking the same precautions to avoid certain substances and activities for at least 30 minutes prior to taking a reading.
Accuracy Isn't the Issue—Practicality Is
Over roughly a week of testing, Samsung’s blood pressure numbers proved reasonably accurate. I tested it on the Galaxy Watch 8 while also using an Omron Blood Pressure Monitor (the same cuff I used for calibration). This testing occurred during the week of my annual physical, when I had my blood pressure professionally checked as well.
The numbers from all tests always stayed within the same ballpark, though Samsung’s measurements sometimes skewed higher by as much as 5 to 10 points on both systolic (the bigger number indicating the pressure in your arteries when your heart is beating) and diastolic (the lower number indicating the pressure between beats) values.
Most of the time, that deviation isn’t a big deal, though on one test, the Galaxy Watch 8 put my blood pressure at 124 over 74, while the cuff said it was 116 over 71. A typical benchmark threshold for blood pressure is 120, with health organizations like the Mayo Clinic calling numbers over that an elevated blood pressure, and numbers below it normal.
Most medical sites advise taking an average of two or more readings on different days to determine your blood pressure, as it can naturally fluctuate a bit from day to day. Given the natural variability of blood pressure, I’d call Samsung's readings accurate enough, even if they gave me one potentially worrisome number.
My bigger issue comes from its practicality, or lack thereof. You need to own a separate blood pressure monitor to use your Galaxy smartwatch as one. I didn’t own one before testing this feature. Again, you need a separate, dedicated cuff to take three measurements for the initial calibration, and you must repeat this process every 28 days. I’m guessing most folks won’t bother with a feature that requires getting a separate device with a redundant function.
Samsung’s feature has one advantage: It is slightly easier to use than a cuff since it’s presumably already on your wrist.
Different Companies, Same Core Problem
The Whoop MG introduced a similar blood pressure feature when it launched last year, and landed in hot water with the FDA for it. Whoop argues that the feature doesn't require clearance, since it's intended for wellness rather than diagnosis or treatment.
Like the Galaxy Watch, to get started with blood pressure measurements on the Whoop MG, you need to take several calibration readings with another cuff. Unlike the Galaxy Watch, the MG can passively take readings in the background, but it calls those numbers estimates and doesn’t offer any advice based on your readings.
Apple doesn’t explicitly measure blood pressure on its watches, but it launched FDA-approved hypertension notifications on its more recent models. The feature takes background readings over 30 days and alerts you if you should see a doctor. It doesn’t let you take on-demand readings or even check the measurements it’s taking passively. You also can’t see where it is in its 30-day assessment process. You either get the notification at some point, or you don’t.
The Path to a Truly Useful Blood Pressure Feature
We’re in the early days of blood pressure monitoring on wearables. While the feature is available now on Samsung watches and other devices, all versions I've tested have some pretty significant shortcomings.
For a blood pressure feature to be actually useful, you need to be able to take on-demand readings, and the device needs to run background checks and send you a notification if it detects something worrisome. Calibration with another device should be minimal, and either doable during an ordinary doctor visit, or capable of happening in the background over time. And finally, all parts of the feature should be accurate and reliable enough to actually earn FDA approval.
While none of the current options meet all those criteria, these initial versions could serve as starting points to get things right in the next generation of wearables. In the meantime, at least I now own a blood pressure cuff.