TL;DR: Apple Watch Ultra 3 and compatible models now analyze optical heart-sensor data over 30 days and alert you to signs of hypertension. If you get a hypertension notfication the advices is to track your blood pressure for a week and share your data with your doctors. You can use Cardilog to track your blood pressure and share your health report with your doctor.
Apple Watch Ultra 3 introduces hypertension notifications that can alert you if the watch detects signs of chronic high blood pressure. The algorithm reviews optical heart-sensor data over rolling 30-day windows and surfaces an alert if consistent patterns suggest hypertension.
How it works
Apple’s model analyzes how your blood vessels respond to each heartbeat using the optical heart sensor. It runs passively in the background across 30 days. If signals point to possible hypertension, you receive a notification. This is a health insight, not a diagnosis.
What to do after an alert
Apple recommends confirming with a 7-day set of cuff measurements and sharing the results with your clinician, aligned with current American Heart Association guidance. Log these readings in Cardilog so you can review trends and export a doctor-ready report.
Availability and supported models
Hypertension notifications will be available this month in 150+ countries and regions, including the U.S. and EU, once regulatory clearance finalizes. Supported devices: Apple Watch Series 9 and later and Apple Watch Ultra 2 and later running watchOS 26.
Evidence, limits, and expectations
- Trained on data from multiple studies totaling 100,000+ participants; validated in a clinical study of 2,000+ participants.
- It will not detect all hypertension cases. Apple estimates more than 1 million people with undiagnosed hypertension may receive a notification in year one. Use a cuff to confirm.
Why this matters for high blood pressure management
- Early flagging: Continuous wear increases the chance of catching sustained high blood pressure patterns between clinic visits.
- Behavior change: A timely nudge can drive lifestyle adjustments and prompt proper evaluation.
- Structured follow-up: Seven days of cuff data creates a clear, clinician-friendly picture.
How do I use Cardilog if I get the hypertension notification?
- Download the Cardilog app free from the app store using this link: https://apps.apple.com/app/id6502426413
- After you create an account in the app, take your blood pressure using your blood pressure monitor and log your numbers in the app.
- Add context: In Cardilog, tag readings with notes like stress, exercise, or meds to improve insights.
- See patterns: Track averages, variability, day vs night values, and trends.
- Share a report: Export your Cardilog health report and send it to your doctor before the appointment.