A closed loop electroacupuncture (EA) system monitors any change in sympathetic drive within the body of a patient undergoing EA stimulation. The sensed change in sympathetic drive is then used to adjust at least one parameter of the EA stimulation regimen in an appropriate manner that assists regulation of the patient's autonomic nervous system (ANS). One manner of determining an increase in sympathetic drive is to monitor the body temperature at the skin. A decrease in skin temperature is indicative of increased sympathetic drive and/or exercise stress due to vasoconstriction in the subcutaneous vascular bed. An adjunct to monitoring skin temperature is to monitor subcutaneous tissue impedance. Subcutaneous tissue impedance increases during vasoconstriction. Thus, a sensed change in tissue impedance may be used by itself, or as a compliment to sensed changes in temperature, to provide feedback within the closed loop EA system to adjust the stimulation regimen.
