The Samsung Galaxy Watch Can Finally Measure Blood Pressure in the US.
The Samsung Galaxy Watch has been able to measure blood pressure for years—in theory. Users in the US only recently gained access to this feature as part of a phased rollout, which has finally reached my device. I’ll show you how to set it up, which is more complicated than it might seem, and then tell you what we know about its accuracy.
How to enable blood pressure display on your Galaxy Watch
I spent the past week checking for software updates on my phone, watch, and app store, to no avail. Finally, the Samsung Health app (with the blue-green running man icon) prompted me to “track blood pressure.” This sent me to the app store to download the new version of the Samsung Health Monitor app (with the pink heartbeat icon).
In addition to your phone and Samsung Galaxy watch, you’ll need two things to set up your blood pressure monitoring system: a blood pressure cuff (a regular cuff from a drugstore will do) and a cellular network connection ( not Wi-Fi).
A mobile network connection is required so Samsung can verify that you’re actually located in a country where the company is legally authorized to provide blood pressure monitoring services. This won’t be a problem for most people, but I use my Samsung phone exclusively for testing Samsung wearables, so I’ve never connected it to a cellular network. I also don’t have a physical SIM card in my regular phone to easily replace it, but fortunately, I was able to find a SIM card that I borrowed for a few minutes. After setting up the app, you can disconnect from the cellular network, and the feature will continue to work.
A blood pressure cuff is required to calibrate the watch. After installing the Samsung Health Monitor app and confirming that you’re ready for calibration, the app will prompt you to sit quietly and take three readings using the cuff. Before beginning, the app will warn you to refrain from “exercise, bathing, alcohol, caffeine, and nicotine consumption” for 30 minutes.
Many factors can affect the accuracy of blood pressure measurements , so I already knew to sit with my legs uncrossed, not have a full bladder, and make sure I sat quietly for at least a few minutes before taking the measurement. The screen the Samsung app showed me after calibration instructed me to sit with my arms on the table for five minutes before taking the measurement.
Even though both measurements are taken simultaneously—the watch on one arm and the cuff on the other—you must remain still until the measurement is complete. Movement after the cuff has finished measuring, but while the watch is still measuring, may result in a zero reading, requiring a repeat measurement. The app doesn’t recommend pausing between measurements, but some blood pressure measurement guidelines recommend waiting approximately two minutes between measurements.
Where can I buy a blood pressure cuff?
For most people, accessing a sphygmomanometer is probably the most inconvenient part of the process. You can use one at the pharmacy or ask your doctor (or, say, a nurse you know who has a sphygmomanometer) to measure your blood pressure for you.
But if you’re interested in monitoring your blood pressure, it probably makes sense to buy your own cuff. A simple wrist cuff shouldn’t cost more than $20-$30, and you can buy one on Amazon or at any pharmacy. I already had one, so I used that.
Samsung recommends using wrist cuffs whenever possible, such as this $49 model . They’re considered slightly more accurate than wrist cuffs. Both types of cuffs inflate and take measurements automatically, so they require no special skills to use, and you don’t even need help taking readings while you’re monitoring your phone and watch.
How accurate are the readings?
While the blood pressure measurement feature is new to the US, it has been available in Europe and South Korea since around 2020. This has given Samsung ample time to conduct several studies on the technology. (Data collection and publication take time, so the newest Galaxy Watch models haven’t yet been published in scientific literature, but older Galaxy Watch models have.)
This 2022 Korean study concluded that the Galaxy Watch’s blood pressure technology exhibits a “systematic bias” in its calibration readings. This means it will underestimate high blood pressure and overestimate low blood pressure. This is the same phenomenon that Whoop MG users complain about—they say the device typically displays blood pressure readings similar to the last measurement taken without the device. So, does the device really add anything?
In 2021, the Korean Society of Hypertension published a document with recommendations for consumer blood pressure monitoring devices. Regarding smartwatches, it is recommended to strictly follow the measurement instructions, which are slightly more detailed than those mentioned above—the society’s full recommendations can be found in the document itself. It also notes that the difference in readings between the right and left wrists can be several points.
But more importantly, the society discouraged the use of smartwatch blood pressure measurements for pregnant women, people with various medical conditions, or those taking certain medications. Blood vessels change during pregnancy in ways that could mislead a smartwatch sensor. Other conditions and medications mentioned include: “aortic insufficiency with a wide pulse pressure, atrial fibrillation with significant beat-to-beat variability, poorly perfused peripheral vascular disease, diabetes, cardiomyopathy, end-stage renal disease, neurological disorders such as hand tremors, bleeding disorders, or use of antiplatelet/anticoagulant medications.”
The society also stated that blood pressure readings obtained from smartwatches are unreliable for blood pressure below 60 mmHg or systolic (the top number) above 160 mmHg, and may not be reliable enough for people who already have hypertension and need monitoring. Despite these caveats, however, they are positive that people who choose to measure their blood pressure with a watch are at least thinking about their blood pressure, and that people with hypertension may be diagnosed earlier because they are regularly checking their blood pressure.