- Google has finally released details on the “Vascular Stress Level” feature included in “Health Guardian,” a health monitoring feature now available for “Google Pixel Watch 3,” “Google Pixel Watch 4,” and “Google Pixel Watch 5” users.
- Specifically, the “Vascular Stress Level” feature analyzes pulse waveforms flowing beneath the skin on the wrist to monitor for trends indicating a continuous rise in blood pressure.
- If a sustained upward trend in blood pressure is detected over several weeks of analysis, the results are notified in a report delivered on the 1st of every month.
On Friday, October 2, 2026, Google released details regarding the “Vascular Stress Level” feature—part of the “Health Guardian” health monitoring feature that finally began rolling out to “Google Pixel Watch 3,” “Google Pixel Watch 4,” and “Google Pixel Watch 5” users in late September 2026.
“Health Guardian” is a new suite of health and safety features that uses AI to track subtle bodily changes in the background, such as blood pressure, insulin resistance, and nighttime breathing quality. It consists of three features: “Vascular Stress Level,” “Metabolic Stress Level,” and “Sleep Breathing Quality.” The AI analyzes data collected while wearing the “Google Pixel Watch 3,” “Google Pixel Watch 4,” or “Google Pixel Watch 5” over periods of several weeks, delivering the results as a report in the “Google Health” app on the 1st of every month.
Specifically, the “Vascular Stress Level” feature within “Health Guardian” analyzes the pulse waveforms flowing beneath the skin of the wrist to monitor for any tendencies of rising blood pressure. Blood pressure increases often progress with almost no subjective symptoms, and it is said that more than 500 million adults worldwide are unaware that their blood pressure is rising.
If high blood pressure persists, it quietly places a strain on the heart, brain, and kidneys, which, if left unchecked, significantly increases the risk of heart disease and stroke. In other words, the “Vascular Stress Level” feature of “Health Guardian” serves to alert users to these hard-to-notice changes at an early stage.
The data analysis for “Vascular Stress Level” utilizes “Waves FM,” an AI model for waveform data developed by Google. By having “Waves FM” interpret the pulse speed and complex waveform shapes measured by the “Google Pixel Watch” series, blood pressure trends can be derived.
Ahead of the “Health Guardian” release, rigorous validation appears to have been conducted by comparing “Waves FM” with “24-hour ambulatory blood pressure monitoring,” which is considered particularly reliable among blood pressure measurement methods.
With “Vascular Stress Level,” if a sustained upward trend in blood pressure is detected through several weeks of analysis, the finding is reported in the monthly report delivered on the 1st of the month. This can prompt concrete actions, such as reviewing lifestyle habits, measuring blood pressure again with a home blood pressure monitor, or consulting a physician.
As mentioned above, “Health Guardian” is currently available to “Google Pixel Watch 3,” “Google Pixel Watch 4,” and “Google Pixel Watch 5” users. However, “Vascular Stress Level” and “Metabolic Stress Level” are also scheduled to roll out as part of “Health Guardian” for the “Fitbit Air,” a screenless wearable tracker by Fitbit, within 2026. Please note that “Health Guardian” on the “Fitbit Air” requires a paid “Google Health Premium” subscription.
Source: Google (https://support.google.com/googlehealth/blog/471065062/google-health-blood-pressure-trends-track-silent-heart-health-shifts-on-wearables)