A system and method for assessing relative proportions of cholinergic and adrenergic nervous receptors in a patient is disclosed. The system includes: an anode, a cathode, and passive electrode for placement on different regions of the patient body. The method generally includes: applying DC voltage pulses of varying voltage values to stress sweat glands of the patient, collecting data representing the current between the anode and the cathode and the potential of the anode, the cathode, and the passive electrode for each of the different DC voltage, and computing data representing the electrochemical skin conductance of the patient. The computed data representing the electromechanical skin conductance of the patient is reconciled with reference data from control patients having known relative proportions of cholinergic and adrenergic nervous receptors. Thus, the relative proportions of cholinergic and adrenergic nervous receptors in the patient can be determined.