Sacral neuromodulation uses gentle electrical stimulation to influence the nerves that help coordinate bladder and pelvic function. During lead placement, a thin insulated wire is positioned near the sacral nerves in the lower back, usually through a small incision or needle opening. The lead delivers mild electrical pulses that can help improve communication between the nervous system and the bladder. In many cases, stimulation is tested first to determine whether symptoms improve before a permanent neurostimulator is implanted. The therapy may be considered for persistent urinary urgency, frequency, urge incontinence, or certain forms of urinary retention when more conservative treatments have not been successful.