Samsung’s latest health monitoring app for your Galaxy Watch promises quick and easy blood pressure monitoring. The trick is that you need to calibrate the initial measurement with a separate blood pressure monitor. During that procedure, you will need to start the blood pressure monitoring feature of your Galaxy Watch that relies on the optical heart rate sensor to measure your blood pressure through pulse wave analysis. Samsung recommends using the Galaxy Watch Active 2 for monitoring and that you repeat the calibration process once a month to ensure accurate readings.
Source: Samsung Newsroom