The present invention concerns an automatic method, as well as the related system and the tools allowing the same to be executed, for measuring and processing blood pressure starting from a detected pressure signal, the method operating in the time domain for discriminating whether the detected signal is an adequate measurement or not and, where it is not, time domain analysis automatically selects a low-pass filter to, possibly iteratively, apply to the detected pressure signal for having correct values and wave form of the blood pressure.