- straining to void
- sensation of incompete voiding
- urinary retention
- incontinence (overflow or urgency)
- neurologic disease
- muscle disease or failure (includes the detrusor (bladder) muscle or muscles of the pelvic floor)
- bladder outlet obstruction (most commonly benign prostatic hyperplasia in men) [2,3]
Unlike OAB, there are no good treatments for UAB. Therefore UAB remains an underappreciated entity and therefore is lacking in understanding and concensus regarding its diagnosis and treatment. Previous attempts at classifying UAB used the terminology detrusor underactivity (DU) to indicate an inability of the detrusor (or bladder) muscle to contract with enough force to expel urine. Recent studies indicate the UAB is more common than previously predicted.
- In a study of 1,179 men and women older than 65 years-old with non-neurogenic voiding dysfunction and lower urinary tract symptoms (LUTS) 
- 40% of men and 13.3% of women had DU (similar to UAB)
- the proportion of patients with DU increased with age
- A study of 181 elderly patients with LUTS identified DU in 48% of men and 12% of women. 
- 40% of men in this study had bladder outlet obstruction (BOO), only 10% of men with DU had BOO
 Chapple CR, Artibani W, Cardozo LD, et al. The role of urinary urgency and its measurement in the overactive bladder symptom syndrome: current concepts and future prospects. BJU Int 2005;95:335–40.
 van Koeveringe GA, Vahabi B, Andersson KE et al: Detrusor underactivity: a plea for new approaches to a common bladder dysfunction. Neurourol Urodyn 2011; 30: 723.
 Osman NI, Chapple CR, Abrams P et al: Detrusor underactivity and the underactive bladder: a new clinical entity? A review of current terminology, definitions, epidemiology, aetiology, and diagnosis. Eur Urol 2014; 65: 389.
 Jeong SJ, Kim HJ, Lee YJ et al: Prevalence and clinical features of detrusor underactivity among elderly with lower urinary tract symptoms: a comparison between men and women. Korean J Urol 2012; 53: 342.
 Abarbanel J and Marcus EL: Impaired detrusor contractility in community-dwelling elderly presenting with lower urinary tract symptoms. Urology 2007; 69: 436.