Can an Apple Watch or iPhone measure blood pressure?
Short answer: no. An iPhone can't measure blood pressure, and an Apple Watch doesn't give you a reading either, though it can now warn you about possible hypertension. Here's what each one does, and the setup that actually works.
What the Apple Watch does
Since September 2025, Apple Watch has offered hypertension notifications, a feature cleared by the US FDA. It works differently from a cuff:
- It uses the watch's optical heart sensor to look at how your blood vessels respond to each heartbeat.
- It analyses that data in the background over 30-day periods.
- If it sees consistent signs of high blood pressure, it sends a notification.
What it doesn't do: show a blood pressure number. There's no systolic or diastolic reading, and no notification doesn't mean your blood pressure is normal. Apple is clear that the feature won't catch everyone with hypertension and isn't meant for diagnosis.
It's available on Apple Watch Series 9 and later and Ultra 2 and later, for people 22 and older who aren't pregnant and haven't already been diagnosed with hypertension. You turn it on from the Health Checklist in the Health app.
After a hypertension notification
Apple's advice is to measure with a blood pressure cuff for seven days and share the results with your doctor. In practice:
- Get a validated upper-arm monitor (pharmacies stock them; see our guide to measuring at home).
- Measure morning and evening for 7 days, two readings each time.
- Log every reading, in the Health app, on our printable 7-day log or in an app.
- Leave out day 1, average the rest, and take the results to your doctor. A home average of 130/80 or higher is the threshold for high blood pressure.
Apps that claim to measure blood pressure
Search the App Store for "blood pressure" and you'll find apps suggesting you can check your blood pressure by putting your finger on the camera. An iPhone can't measure blood pressure. Its camera can pick up your pulse from changes in skin colour, but that doesn't contain enough information to work out the pressure in your arteries.
These apps either produce numbers that aren't accurate, or quietly say "for entertainment only" in the small print. Regulators have taken action against apps making such claims. The danger is real: a reassuring fake reading can delay treatment for someone who needs it.
Apps that are useful are honest about it: they're logs for readings taken with a real cuff, or companion apps from cuff makers like OMRON or Withings that receive readings over Bluetooth.
Other cuffless devices
Several smartwatches and bracelets estimate blood pressure without a cuff, usually after calibration with a regular cuff. The technology is improving, but the 2025 AHA/ACC guideline doesn't yet recommend cuffless devices for diagnosing or managing high blood pressure, because their accuracy hasn't been proven well enough. If you use one, check it regularly against a validated cuff and don't make treatment decisions on its numbers alone.
What actually works
The combination doctors want to see is simple:
- A validated upper-arm cuff for the measurement
- A consistent routine: morning and evening, sitting correctly, two readings each time
- A log that turns those readings into averages your doctor can use
The Apple Watch's role is to tell you when to start that routine. The cuff and the log do the rest.
Choosing a blood pressure app for iPhone
If you'd rather log on your phone than on paper, look for an app that:
- Doesn't claim to measure blood pressure itself
- Syncs with Apple Health, so readings from your cuff's own app come in automatically and nothing is locked into one app
- Reminds you morning and evening, because a week of readings with gaps is less useful
- Calculates the 7-day average the way the guideline describes, rather than just plotting a chart
- Exports a report (PDF) you can show or send to your clinic
- Respects your privacy: no account required, no ads, and clear about where your health data goes
We built Blood Pressure Log+ around that list. Logging, reminders and Apple Health sync are free; the doctor report is part of Premium. Whatever app you choose, check it against the list above.
Sources
- American Heart Association: Top things to know: 2025 high blood pressure guideline
- American Heart Association: Home blood pressure measurement instructions (PDF)
- US Validated Device Listing (validatebp.org)