Underactive bladder (UAB) is an important and complex urological voiding condition resulting from the urodynamic finding of detrusor underactivity (DUA). It can manifest in a wide range of lower urinary tract symptoms (LUTS), from voiding to storage complaints, and can overlap with other conditions, including overactive bladder and bladder outlet obstruction.1 DUA is a common yet under-researched bladder dysfunction. The reported prevalence of DUA is 25%–48% and 12%–24% in elderly men and women with LUTS, respectively, based on the arbitrary urodynamic criteria for DUA.2 DUA is defined by the International Continence Society as a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or failure to achieve complete bladder emptying within a normal time span.3 Urodynamics is the diagnostic tool for DUA; it is an invasive test that might not be available in all health care settings. The typical urodynamic findings of DUA are a low-pressure, poorly sustained detrusor contraction and low flow.4 Recently, there has been renewed interest in DUA, the associated symptoms, and potential treatments.