A system and method for treating a patient suffering from chronic hypertension. Electrical therapeutic energy is delivered to a nerve branch of a renal artery of the patient, thereby treating the chronic hypertension. Another system and method for treating a medical condition of a patient. Electrical stimulation energy is delivered to a stimulation site on the wall of a blood vessel, thereby evoking a compound action potential in a nerve branch associated with the blood vessel, sensing the evoked compound action potential at a sensing site on the wall of the blood vessel, identifying a circumferential location of the nerve branch as being adjacent the stimulation site or sensing site based on the sensed compound action potential(s), and delivering therapeutic energy to a therapeutic site on the wall of the blood vessel adjacent the circumferential location of the nerve branch, thereby modulating the nerve branch and treating the medical condition.