MADRID, Feb. 13 (EUROPA PRESS) – High blood pressure remains one of those health problems that progress silentlyMany people live for years with blood pressure above the recommended level without noticing, because it doesn't usually present clear symptoms. At the same time, in Spain and the rest of Europe, more and more people are wearing smartwatches on their wrists. Apple Watch health features that measure pulse, heart rate or sleep, and that begins to issue warnings related to the heart and blood pressure.
In this context, the Apple Watch has incorporated a specific function of notifications of possible hypertensionDesigned to send alerts when the blood flow patterns recorded by the watch suggest elevated blood pressure readings, the device, which works without an inflatable cuff and relies on optical sensors, has been authorized by the U.S. Food and Drug Administration (FDA). This has sparked debate about its actual role in the early detection of hypertension and its potential impact in Europe if it becomes widespread. More details on these blood pressure alerts have been published by specialized media.
How the Apple Watch tries to detect hypertension
Apple's new feature doesn't measure blood pressure like a traditional blood pressure monitor, but passively analyzes blood flow through the watch's optical sensors. In that sense, the system integrates with the Hypertension monitoring on Apple Watch to collect continuous data that feeds the algorithm. From this data, an algorithm looks for patterns consistent with high blood pressure readings and, when certain criteria are met, generates a notification to the user warning of possible hypertension.
Unlike devices with a cuff, which compress the arm and provide a specific systolic and diastolic blood pressure reading, the Apple Watch simply indicates that There could be a problem with high pressure.Apple insists that this is not a diagnostic tool, but a screening system designed to encourage those who receive the alert to see a healthcare professional and have their measurements taken with validated devices; in this sense, the hypertension notifications They should be interpreted with caution.
This approach aligns with an increasingly widespread reality in Europe: millions of people already wear watches daily and for many hours, which allows record data continuously and effortlesslyThis volume of information offers an opportunity to detect cases that might otherwise take years to discover, especially among young adults who rarely check their blood pressure; in fact, The Apple Watch could warn you sooner in certain cases.
However, experts point out that blood pressure is a complex and fluctuating variable, influenced by stress, physical activity, sleep, and even the presence of healthcare professionals. Therefore, European guidelines continue to require repeated measurements with cuff, both in the doctor's office and at home, before confirming the diagnosis of hypertension.
According to a validation study conducted by the company itself, the algorithm's results are far from perfect: approximately 59% of people with undiagnosed hypertension would not receive any alert (false negatives), while around 8% of those who do not have the disease could receive an erroneous notification (false positives). These figures necessitate putting the role of these notifications into context.
What does scientific research say about these alerts?
A recent analysis, led by researchers from the University of Utah and the University of Pennsylvania and published in the Journal of the American Medical Association, has focused on estimating What real impact could the Apple Watch have on the diagnosis of hypertension? if this function were applied on a large scale in adults without a prior diagnosis.
The team used data from a representative health survey of the American adult population to simulate different scenarios. They focused on adults over 22 years of age who were not pregnant and unaware that they had hypertension—that is, the group that was potentially They would benefit most from early warning Issued by the watch. Based on the actual prevalence of hypertension in each age group and demographic, they calculated how the probability of having the disease would change after receiving—or not receiving—an alert.
Among those under 30, data shows that receiving a notification increases the likelihood of developing hypertension from an estimated 14% to 47%. Meanwhile, Not receiving an alert reduces that probability to 10%.In other words, in this segment of the young population, a warning represents a significant change in the estimated risk, while the absence of notification is relatively reassuring.
In people over 60, the scenario changes significantly. In this group, with much higher baseline rates of hypertension, an alert increases the estimated probability from 45% to 81%. However, Not receiving a warning barely reduces the riskIt stands at around 34%, still very high. For older people, therefore, the message is clear: lack of notification cannot be interpreted as synonymous with having normal blood pressure.
The authors also analyzed differences between racial and ethnic groups, reflecting disparities observed in Europe based on origin, income level, or social conditions. Among non-Hispanic Black adults, receiving an alert increased the likelihood of hypertension from 36% to 75%, while Not receiving it only lowered it to 26%.In Hispanic adults, the estimated risk increased from 24% to 63% with a notification, and decreased to 17% if there was no notification.
This pattern highlights that as the prevalence of undiagnosed hypertension increases in a specific group, so does the likelihood that an alert corresponds to a real case. At the same time, The absence of warning loses its reassuring value in people with more risk factors, something that can be extrapolated to many groups in Europe with a high burden of cardiovascular disease.
Advantages and limitations of using the Apple Watch to monitor blood pressure
Researchers emphasize that hypertension remains the leading preventable cause of heart disease worldwide. In Europe, where population aging is marked and sedentary lifestyles remain prevalent, any tool that increases the opportunities for early detection can have an impact on public health.
From that perspective, the Apple Watch and other smartwatches offer several advantages. For one thing, they allow monitor long-term trends without the user having to do anything other than wear the device. On the other hand, they have a "constant reminder" effect that encourages many people to pay more attention to their health, walk more, or consult a doctor when they receive an unusual alert.
However, these same devices have significant limitations. Optical sensor technology doesn't achieve the accuracy of a blood pressure monitor with a cuff and, as Apple's validation data shows, can produce both false positives and false negativesThis means that some people will be unnecessarily alarmed, while others, even with high blood pressure, will not be alerted at all. Furthermore, the appearance of a new patent It raises questions about how the technology and its accuracy will evolve.
The study authors emphasize that this tool should be understood as a complement to, not a substitute for, traditional measurements. Clinical guidelines recommend screening for adults without significant risk factors. have your blood pressure checked every three to five years Before age 40, and at least once a year thereafter. These guidelines don't change because there's a watch that sends alerts; if anything, the notifications should motivate people to follow them more rigorously.
One of the risks experts point out is a false sense of security. If someone interprets the lack of alerts from their Apple Watch as meaning their blood pressure is fine, they might stop going to regular check-ups or never even get their blood pressure checked with a validated cuff. In practice, this would mean missing valuable opportunities for early diagnosis and treatment, which is especially worrying for older adults and those who already have other cardiovascular risk factors.
What should patients and doctors do in response to a clock alert?
For healthcare professionals, the emergence of this Apple Watch feature presents a scenario already being seen in European clinics: patients arriving with their phones or watches in hand, saying they've received a warning. Researchers recommend treating these alerts as a starting point for a more comprehensive evaluationnot as a diagnosis in itself.
The protocol suggested by the team led by Adam Bress is quite clear. When a person arrives at the clinic after a notification of possible hypertension, the first step is to perform a blood pressure measurement in the doctor's office Using a high-quality cuff, and following the recommendations for positioning, prior rest, and number of readings. If the values ​​are high or inconclusive, it is advisable to supplement with measurements taken outside of a healthcare setting.
This assessment outside the doctor's office can be done using a validated home blood pressure monitor, with repeated readings over several days, or through 24-hour ambulatory blood pressure monitoring (ABPM), which is usually considered the gold standard for confirming hypertensionBased on the results, a decision is made as to whether to start pharmacological treatment, reinforce lifestyle changes, or simply continue monitoring blood pressure.
In Europe, where access to primary care and community nursing is key, these types of alerts can help people who rarely went to the doctor. come into contact with the healthcare system before complications arise. Bress and his colleagues emphasize that if the watch alerts lead to more diagnoses confirmed by standard methods, the overall balance will be positive.
However, the authors warn that healthcare systems must prepare to manage this new influx of wearable-related consultations. Clear protocols will need to be established for prioritize patients at higher riskto avoid unnecessary tests and ensure that those who truly need follow-up are not lost on the waiting list. In countries with limited resources or strained primary care, this point can be particularly critical.
The research team plans to continue with follow-up studies to estimate how many adults would receive false positives and false negatives with this feature, broken down by region, education level, income, and other social factors. This information will help assess which groups are most at risk. Alerts can be more useful and where technology needs adjusting or health education needs strengthening; initiatives such as the New patent for measuring blood pressure from the clock.
Ultimately, the Apple Watch's role in detecting hypertension will depend both on the evolution of its algorithms and how well it integrates into daily clinical practice. Between the promise of continuous monitoring and the risk of generating unwarranted confidence, the key will be for users and professionals to employ it as an additional aid, without losing sight of the fact that blood pressure confirmation still requires a traditional blood pressure monitor.
