System and method for the simultaneous and non-invasive estimation of blood glucose, glucocorticoid and pressure levels. It comprises an activity module detector for a digitalized signal acquired by a sensor, representing the distal heartbeat of a person, selecting a segment of consecutive signal samples of fixed duration Swindow(t) and using the same to generate sub-windows Sframe(t, n) of shorter duration a signal processing module which receives the two signals Swindow(t) and Sframe(t, n) and which delivers a vector XF at its output with the parameters of a physiological model and module based on automatic learning, which receives the XF vector and information on a persons characteristics and provides an estimation of blood glucose levels (BGL), systolic pressure levels (SPL), diastolic pressure levels (DPL) and glucocorticoid levels (GCL) at its output.