Sacral neuromodulation (SNM) is a therapy system used to improve bladder function, including in people with overactive bladder (OAB). It is safe and can improve quality of life. SNM helps improve symptoms through direct modulation of nerve activity; it involves electrically stimulating the sacral nerves that carry signals between the pelvic floor, spinal cord and the brain and is thought to normalise neural communication between the bladder and brain.