(UroToday.com) Underactive bladder (UAB) has been under-discussed and under-researched for years, despite the fact it is common, severe, and lacks effective treatment. It is one of the greatest areas of unmet need and yet has the greatest opportunity for advancement in functional urology. Dr. Christopher Chapple recommended the 2020 review by Mike Chancellor. The etiology of UAB is complex, many times there is no diagnosis or cause and it is termed “idiopathic” detrusor underactivity. Detrusor underactivity (DUA or DU) is diagnosed by urodynamics based on pressure-flow characterized by low-pressure, and/or poorly sustained detrusor contraction in combination with low urinary flow.