apparatuses for treatment of hyperhidrosis , raynaud &# 39 ; s phenomenon , cerebral ischemia and asthma and hypertension by nerve stimulation are disclosed . in particular , the invention relates to the improvement of these conditions by stimulating at least one ganglion selected from the group consisting of t - 1 through t - 4 ganglia , cervical ganglia , renal nerve or combinations thereof with an implantable , wireless , battery - less and lead - less stimulator . stimulations of the ganglion may be carried out with pulsed radiofrequency , thermal energy or optical irradiation .