Apparatus and methods for deactivatingrenal nerves extending along a renal artery of a mammaliansubject to treat hypertension and related conditions. Anultrasonic transducer (30) is inserted into the renal artery(10) as, for example, by advancing the distal end of acatheter (18) bearing the transducer into the renal artery.The ultrasonic transducer emits unfocused ultrasound soas to heat tissues throughout a relatively large impactvolume (11) as, for example, at least about 0.5 cm3encompassing the renal artery to a temperature sufficient toinactivate nerve conduction but insufficient to cause rapidablation or necrosis of the tissues. The treatment can beperformed without locating or focusing on individual renalnerves.
