Review of underactive bladder.

In clinical practice, many patients cannot empty their bladders within an acceptable duration. Common complaints include weak urinary stream and incomplete emptying, which may affect quality of life. Bladder emptying requires sufficient detrusor contractile power, velocity, and durability. The urodynamic term for inadequate detrusor contraction is detrusor underactivity (DU). Although this definition was provided by the ICS, it may not be clinically practical. Analogous to the relationship between overactive bladder (OAB) and detrusor overactivity (DO), the symptom complex caused by DU is termed underactive bladder (UAB). Many conditions lead to UAB, such as advanced age, neurogenic bladder and BOO, but the definite pathophysiology directly leading to UAB is still being widely studied without a widely-accepted consensus. The preferred mainstream treatment for increased residual urine volume caused by UAB is intermittent catheterization, while pharmacotherapy is still disappointing after decades of development. There are no studies on surgical treatment for UAB with an acceptable level of evidence. We reviewed the recent literature on UAB and DU to provide a comprehensive discussion of the related presentation, etiology, diagnosis and management.