Among many diseases that can exist in the body without a person knowing about it, hypertension is arguably the most
common. There is an estimate that it affects over 1.4 billion people across the globe and almost 40 per cent of them are
not even aware that they have it. It is to tackle this problem that Apple added a new hypertension notification feature
to Watch a few months ago. The Watch Series 9 and newer and Apple Watch Ultra 2 and newer are supported. Now, after
regulatory approvals, the feature is rolling out in India.
Apple says the hypertension notifications feature will alert users if signs of chronic high blood pressure, or
hypertension, are detected. This is a one-time alert feature. It uses specific algorithms to monitor data collected
through the optical heart sensor on the Apple Watch. This data is analysed to see how a user’s blood vessels respond to
the beats of the heart and after an analysis that spans over 30 days, the Watch will notify users if it detects
consistent signs of hypertension.
“As a clinician in a cardiologist, it's something that we see so often that people come in having had hypertension for
years and years and just not know it because it's an asymptomatic disease,” Adam Phillips, a cardiologist at Apple, told
India Today Tech. “So having this feature at the scale that Apple operates at available to our users is really huge.”
Phillips says that the feature has been developed with a lot of care and thoroughness and false positives have been
minimised greatly. “We develop our feature with a lot of rigour in both the development phase and the clinical
validation phase, and we developed (Hypertension Notification) with over a hundred thousand participants in development
and then clinically validated it with over 2000 participants,” he says. “We expect to notify over a million people in
The feature may prove particularly useful for Watch users in India, a country where hypertension is almost endemic, with
reports noting that one in every third Indian is likely to have hypertension. And yet, the diagnosis of the disease
remains rather poor because it rarely shows up with symptoms in early stages.
Alert but no blood pressure monitoring
As the feature is rolling out, it is important to understand what it does and what it doesn’t. It is quite simple. The
feature, as its name — Hypertension Notification — suggests, is a one-time alert that can help Watch users detect a
condition that they don’t know about. To do this, as noted earlier, the Watch relies on data collected through a heart
rate sensor. In that sense, the feature does not perform an on-demand blood pressure recording like the machines with
To enable the feature, users will have to set it up in the Health app. During the setup process they will be asked to
fill in certain details such as age. Only users 22 or older can use this feature. Also if you already have hypertension
and you take drugs for it, the Hypertension Notification is not for you.
Once it finds latent hypertension, the Watch will encourage users to go for a thorough test. Phillips says that once the
Watch detects hypertension, “it will give (users) next steps that are really actionable for, for them to go check their
blood pressure (and) log in at home” using a regular blood pressure machine.