Can a smartwatch measure blood pressure?
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Not in a way you should act on. Apple Watch can send a hypertension notification after 30 days of data, and it doesn’t show a number. In its validation study it alerted about 41 percent of people with hypertension. To know your blood pressure, you still need a cuff.
Where the guideline stands
The 2025 US guideline doesn’t recommend cuffless devices, including watches, for diagnosing or treating high blood pressure. It says that’s because the evidence is mixed and the devices lack outside validation. That goes for any device that gives you a number without a cuff.
What each watch does
| Watch | What you get | Needs a cuff? | Stated limits |
|---|---|---|---|
| Apple Watch, Series 9 or later, Ultra 2 or later | A notification after a 30-day review of optical sensor data, and no number | Yes, Apple prompts you to use one for 7 days after a notification | For adults 22 or older, not pregnant, with no hypertension diagnosis. Availability varies by region. |
| Samsung Galaxy Watch | An estimated number where the feature is offered | Yes, to calibrate every 28 days | Samsung’s US support material says it cannot be used to monitor blood pressure in the United States. |
How accurate the Apple notification is
In the study behind the feature, researchers checked the watch against home cuff monitoring over 30 days.
| Group | Result |
|---|---|
| People with undiagnosed hypertension | 41.2 percent got an alert |
| People without hypertension | 92.3 percent got no alert, so 7.7 percent got a false one |
If you get an alert, pay attention to it. But getting no alert doesn’t tell you much, because more than half of the people with hypertension in the study never got one. Apple also says that not everyone with hypertension will receive a notification. In a 2026 analysis in JAMA, researchers looked at what the feature could mean for US adults without a diagnosis, and they used these same accuracy figures.
The feature isn’t meant for people who already have a diagnosis, so it can’t tell them whether their treatment is working.
What to do if you get a notification
- The notification on its own isn’t an emergency, but it means you should measure.
- Get an upper-arm cuff from a validated list.
- Take a seven-day home week, morning and evening.
- Enter the numbers in the home average tool.
- Take the average and the notification to your doctor.
What to do if you get none
Measure anyway. A week of home measurements every so often doesn’t cost much, and it catches high blood pressure that a watch misses. Many people with high blood pressure feel nothing, and some measure normal at the clinic too, which is called masked hypertension.
Apple also notes that the watch can’t detect a heart attack. If you have chest pain, shortness of breath, back pain, weakness, numbness, vision change or trouble speaking, call emergency services, whatever your number is.
5 sources
- Apple Support, Hypertension notifications on your Apple Watch, 2026support.apple.com
- JAMA, on the Apple Watch hypertension notification validation study, 2026jamanetwork.com
- Cohen JB et al., Impact of a Smartwatch Hypertension Notification Feature for Population Screening, JAMA, 2026pubmed.ncbi.nlm.nih.gov
- Samsung, Check your blood pressure using a Galaxy smartwatch, US support, checked 2026samsung.com
- Brown C, Clark D, Jones DW, Updates in the 2025 AHA/ACC Hypertension Guideline, Current Hypertension Reports, 2026pmc.ncbi.nlm.nih.gov
