SPECIALTY TOPICS · GUIDE
Blood Pressure Wearables and Cuffless Devices
How cuffless blood pressure watches, rings and patches work, what the FDA and the European Society of Hypertension say, and why a cuff reading remains the reference.
Content last updated . This page has not been medically reviewed.
Back to BiohackingStart here: do not treat a cuffless number as your blood pressure
On September 16, 2025 the FDA warned consumers not to use unauthorized blood pressure devices, including software features on wearables such as smartwatches and smart rings that claim to measure blood pressure. It said inaccurate readings can lead to errors in diagnosing high or low blood pressure and to delayed treatment, and that inappropriate medication changes are a risk. [1] Do not start, stop or change any medicine based on a wearable reading. If you have chest pain, severe headache, weakness on one side, trouble speaking or severe shortness of breath, call 911 in the US rather than checking a device.What a cuffless device does
A cuff device squeezes the arm and detects pressure changes. A cuffless device skips that and estimates pressure from other signals, mostly light-based pulse waves (photoplethysmography, see optical heart-rate sensing). In one systematic review, 81.3% of the devices used photoplethysmography. [2] Those methods often need individual calibration against cuff readings, which makes accuracy hard to judge, and many studies claiming accuracy used inadequate testing. [3]| Number shown | Direct or derived |
|---|---|
| Pulse waveform, pulse rate | Direct (from the light sensor), subject to motion and fit |
| "Blood pressure" in mmHg from a watch, ring or patch | Derived by algorithm, often needing cuff calibration |
| "Possible hypertension" notification | Derived pattern flag, not a measurement |
What studies show
A systematic review (studies to December 2019; 16 studies, 15 devices, 974 participants) found that eight devices had mean systolic and diastolic bias under 5 mmHg versus a reference, but precision was not assessed, and the pooled systolic difference was 3.42 mmHg with a very wide range (95% CI -2.17 to 9.01; I2 95.4%). The authors said variation in protocols limited comparisons and that real-life validation is needed before clinical recommendation. [2] A 2026 study of a photoplethysmography-based upper-arm cuffless device in 50 mostly normal-pressure adults found the limits of agreement for awake-versus-asleep change were -8.0 to 11.2 mmHg for systolic pressure, and said full validation is required before clinical use. [8]Overall label: insufficient evidence that cuffless wearables can replace cuff measurement; mixed and device-specific for individual products.
Accuracy is not benefit
No source read for this page shows that wearing a cuffless device improves health outcomes. High blood pressure usually has no symptoms, which is why accurate measurement matters. [1][9] For diagnosis, the NHS describes measurement with an inflatable arm cuff, followed if needed by home monitoring or a 24-hour portable monitor. [10][9] For home cuffs versus wearables, see blood pressure: home cuffs and wearable estimates.Who should be careful
Anyone taking blood pressure medicine, or with heart or kidney disease, pregnancy or a history of stroke, should ask their clinician which device to use. The FDA advises talking to your provider about an appropriate authorized device if your care depends on accurate measurements. [1] A reassuring wearable number can delay treatment; an alarming one can lead to unneeded changes. [1]How to judge a claim
Check the FDA 510(k) database for the exact device name and function, and ask whether it needs calibration and in whom it was validated. See how validation against a clinical reference works and consumer data versus clinical measurements.Frequently asked questions
Are smartwatch blood pressure readings accurate?
The FDA warned in 2025 against unauthorized wearable features claiming to measure blood pressure. [1] Experts say accuracy questions must be settled first. [6]
Does the Hypertension Notification Feature measure my blood pressure?
The FDA record names it notification software. [5] Notifications are a pattern flag, not a mmHg reading.
Can I use a cuffless device instead of a cuff?
Not for diagnosis or medication decisions based on the sources read: the ESH working group did not recommend cuffless devices for diagnosing or managing hypertension. [6]
Why do cuffless devices need calibration?
They estimate pressure indirectly and typically require individual calibration with cuff readings, which complicates accuracy testing. [3]
How do I check whether a device is FDA-authorized?
Search the FDA 510(k) database by device name; authorized devices will generally have product code DXN. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
How to read the evidence labels
Labels used on this page: established, mixed, insufficient evidence, marketing claim.
What the regulators and experts say
- FDA safety communication (2025). Many over-the-counter blood pressure devices lack FDA marketing authorization, so the FDA has not evaluated their safety and effectiveness. Authorized devices generally carry product code DXN in the FDA's 510(k) database. The FDA says such devices are not covered by its general wellness policy because they are not solely for wellness and not low risk. [1]
- FDA draft guidance. The FDA lists draft recommendations (page current as of 01/22/2026) on clinical performance testing for cuffless non-invasive blood pressure devices (docket FDA-2025-D-0851). It is a draft, not final policy. [4]
- One specific clearance. The FDA 510(k) database lists Apple's Hypertension Notification Feature (K250507), classified as "Hypertension Machine Learning-Based Notification Software" (product code SFR), with a decision of substantially equivalent on 09/11/2025. [5] A notification feature is a different function from a blood pressure reading, and clearance of one feature does not apply to other watches or features.
- European Society of Hypertension (2022). Its working group noted that existing guidelines do not recommend cuffless devices for diagnosing or managing hypertension, and that fundamental questions about accuracy, performance and implementation must be answered before clinical use is recommended. [6] In 2023 it defined six validation tests, including checks of calibration stability over time and of tracking blood pressure changes. [7]
References
- U.S. Food and Drug Administration, Do Not Use Unauthorized Devices for Measuring Blood Pressure: FDA Safety Communication, issued September 16, 2025. Read 2026-10-22.
- Wearable cuffless blood pressure monitoring devices: a systematic review and meta-analysis, Eur Heart J Digit Health 2022 (PMID 36713001). Read 2026-10-22.
- Cuffless Blood Pressure Measurement: Where Do We Actually Stand?, Hypertension 2025 (PMID 40231350). Read 2026-10-22.
- U.S. Food and Drug Administration, Cuffless Non-invasive Blood Pressure Measuring Devices: Clinical Performance Testing and Evaluation (draft guidance, docket FDA-2025-D-0851), page current as of 01/22/2026. Read 2026-10-22.
- U.S. Food and Drug Administration, 510(k) Premarket Notification K250507, Hypertension Notification Feature (HTNF). Read 2026-10-22.
- Cuffless blood pressure measuring devices: review and statement by the European Society of Hypertension Working Group on Blood Pressure Monitoring and Cardiovascular Variability, J Hypertens 2022 (PMID 35708294). Read 2026-10-22.
- European Society of Hypertension recommendations for the validation of cuffless blood pressure measuring devices, J Hypertens 2023 (PMID 37303198). Read 2026-10-22.
- Nocturnal Blood Pressure Dipping in Adults: A Comparison Between Cuffless and Ambulatory Blood Pressure Monitoring, Am J Hypertens 2026 (PMID 42768439). Read 2026-10-22.
- NHS (UK), High blood pressure (hypertension), last reviewed 19 July 2024. Read 2026-10-22.
- NHS (UK), Blood pressure test, last reviewed 25 November 2025. Read 2026-10-22.
Education, not medical advice. This page is for general information. It does not diagnose or treat any condition and is not a substitute for care from a qualified health professional. Natural does not automatically mean safe. Ask a clinician or pharmacist before changing your care, especially if you take medication, are pregnant or breastfeeding, or have a health condition.