On Health

Smartwatch Hypertension Notifications: How Seriously Should You Take It?

May 12, 2026

Wearables, such as smartwatches and rings, now track far more than steps. Some devices offer ECG features, which manufacturers say can detect issues such as irregular heartbeat and now, hypertension.

A hypertension notification feature was approved by the U.S. Food and Drug Administration in September 2025. The Apple smartwatch hypertension notification feature is designed to alert users to possible hypertension and prompt further evaluation, according to the company.

The difference between an alert from a wellness device and a blood pressure reading from a medical-grade device is night and day, according to Dr. Eleonora Avenatti, cardiac prevention and obesity specialist at Houston Methodist.

So just how seriously should you take a hypertension notification?

How hypertension notifications work

Blood pressure is a measurement of the force of your blood pushing against your blood vessel walls. A blood pressure measurement includes two numbers: a top number (systolic blood pressure — the pressure of blood when the heart is contracting) and a bottom number (diastolic blood pressure — the pressure of blood when the heart is relaxed). Both are measured in millimeters of mercury (mm Hg).

Apple uses a light-based sensor that measures heart rate to look for blood flow patterns as your heart beats, calculating blood pressure using a proprietary algorithm. Users won’t receive a top or bottom number, nor are they able to do blood pressure spot checks. A user will only receive a notification if their data suggests possible high blood pressure. Individuals previously diagnosed with hypertension are restricted from using the feature, as the FDA only cleared the feature for potentially identifying undiagnosed high blood pressure.

Samsung is bringing its blood pressure notification feature to the U.S. market, with a key difference. The blood pressure function for these smartwatches requires you to take a reading using an upper arm cuff (an add-on purchase) and recalibrate the watch every month to use the feature. In-between using the cuff, the watch standard heart rate feature will estimate changes to blood pressure. Samsung says its sensor is capable of measuring both systolic and diastolic blood pressure.

It’s important to note that both Apple and Samsung say that their products are not medical devices and that their blood pressure features should only be used for overall wellness.

“Medical-grade devices are subject to strict controls and validation. We know how they work and that their readings are precise and reliable, meaning that they specifically measure what they're supposed to measure and under different conditions the number will remain the same,” Dr. Avenatti says. “Wearable smartwatches don't have the same degree of validation, but they can be helpful to track yourself over time, see trends and raise red flags.”

Dr. Avenatti says the notifications smartwatches provide can help alert you to an issue, but only medical grade devices can be used for diagnosis and treatment under the supervision of doctor.

“Wearables cannot be used and should not be used for diagnostic purposes,” Dr. Avenatti says. “We are not at the place where we can use the wearable devices to make a diagnosis of arrhythmia or blood pressure disorders.”

How accurate are the notifications?

The initial validation study by Apple showed that just over 41% of people with undiagnosed high blood pressure would receive a hypertension alert on their smartwatch, and about 8% of undiagnosed individuals would receive a false alert. This was done in comparison to 15 to 30 days of home blood pressure monitoring.

However, a February 2026 modeling study in Journal of American Medical Association estimated the accuracy of hypertension alerts using sensitivity and specificity data from the Apple’s validation study and applied it to the National Health and Nutrition Examination Survey (NHANES), a large multiyear U.S. health survey. The JAMA study included NHANES data from the population eligible to use the hypertension feature: adults 22 years and older, who were not pregnant, and did not have a previous hypertension diagnosis.

The JAMA analysis estimated an alert meaningfully raises the probability that someone has hypertension. The positive predictive value was 69.1%, meaning about 7 in 10 people who receive an alert were estimated to actually have hypertension. For those who don’t receive an alert, there was about a 79% chance they didn’t have hypertension, meaning 21% of users could have hypertension and feel a false sense of safety.

Receiving a notification at age 60 or older raised the probability of high blood pressure from 45% to 81%, while getting that same notification at age 30 or younger increased probability from 14% to 47%. Not receiving a notification in the 30 and younger group lowered the probability of hypertension to 10%, where in the 60+ group the probability only lowered to 34%.

Hypertension rates are much higher in the 60+ group, so many with hypertension could go undetected using the feature. The absence of a notification is not an all-clear signal for your heart health.

“I think that all technology needs the human input,” Dr. Avenatti says. “We’re not supposed to use any of this stuff without our brain turned on and using context. Now, what we do with a notification is a different story, right?”

Why these alerts can be useful — though imperfect

There is room for error with these devices. Some alerts will be false alarms, and many people with high blood pressure may get no alert at all. Apple’s own validation study showed 58.8% of people with undiagnosed hypertension did not receive an alert. Among people without hypertension, 7.7% received an inappropriate alert.

“Guidelines from the American College of Cardiology and American Heart Association, the big cardiovascular societies in the United States, say that the use of wearables is not recommended for the diagnosis and management of high blood pressure.” Dr. Avenatti says. “So, we should not rely on those numbers as it’s not the direct measurement and the way it's extracted from the heart rate and pulsation is proprietary for every single device, and we have no insight on how those algorithms were created.”

However, Dr. Avenatti says that these wearable notifications can be useful if they prompt someone to monitor their health with a provider. That way, there can be a meaningful conversation with your doctor about any symptoms, history and risk factors and any tests needed could be ordered.

“If someone is concerned about a notification or they are worried about a family history of heart disease, I'll say, ‘OK, then we should probably have a deeper look, see what your current situation is,’” Dr. Avenatti says. “With a couple of non-invasive, low-cost heart tests, we can check and see if everything's fine. And from there, they can monitor with a wearable, and if we pick up some red flags, we'll have a different conversation and we'll do a deep dive again.”

For Dr. Avenatti, that is the human element needed to use smartwatch technology effectively.

“We should use the notifications and data from wearables as extra input. It's a window inside our body and we should interpret what the numbers we're seeing in the context of how we are feeling,” Dr. Avenatti says. “Then, take the time and talk about your data, concerns and goals with your doctor and the conversation is much more productive.”

What to do if your watch flags (or doesn’t flag) possible hypertension

A hypertension notification is a good reason to seek care to get a validated blood pressure reading with a medical grade blood pressure cuff and talk with a health care professional. That is especially true if:

You have heart disease risk factors.
You have been told in the past that your blood pressure was borderline high.
You’re noticing symptoms that concern you.

It is also worth bringing up if you keep getting similar alerts over time, even if you feel fine.

“These devices can see trends, and I think that's very important, and it can raise the red flags and potentially say, ‘Hey, something's off, why don't you check?’” Dr. Avenatti says. “That check has to be with a medical-grade health care device. That check has to be talking to a physician and see if there's an underlying issue.”

A practical approach looks like this:

Treat the notification as a prompt, not a diagnosis.
Confirm your blood pressure with a validated cuff-based reading.
Bring the alert into a broader conversation about your symptoms, family history and overall heart health with your primary care provider or a cardiologist.

Just as important, do not assume that no alert means your blood pressure is normal. The JAMA study demonstrated the absence of an alert doesn’t strongly rule out hypertension — some people with undiagnosed high blood pressure will receive no notification. That is why routine screening with validated blood pressure measurement still matters.

“These are incredibly good tools that needs to be used with two grains of salt,” Dr. Avenatti says. “They're not medical devices and can’t replace the health monitoring you get from a physician.”