Techniques are described for integrating blood pressure measurement (BPM) into a portable electronic device. For example, an input interface of the device includes an integrated force sensor. Human-discernable feedback is output to the user, while using the force sensor to monitor fingertip pressure being applied by the user on the input interface, to guide the user into a first condition in which capillary fingertip blood flow (CFBF) is occluded. The human-discernable feedback is then output to the user, while continuing to use the force sensor to monitor the fingertip pressure, to guide the user into one or more subsequent conditions that allow non-occluded CFBF signals to be sensed by one or more sensors (e.g., the force sensor, an optical fingerprint sensor, etc.). The sensed non-occluded CFBF signals can be used to generate one or more CFBF-based BPM readings for the user (e.g., which can be calibrated to arterial BPM).
