Anatomical or functional obstruction of the urethra or the bladder neck, such as urethral stricture or poor opening, as a consequence of e.g. a trauma or an operation.
Detrusor sphincter dyssynergia in a neurogenic bladder associated with, for example, spinal cord disease or injury.
Poorly contracting detrusor muscle (detrusor myopathy) due to an emptying obstruction and/or overdistension
In women, prolapse of the uterus or urethral mucous membrane
Measurement of residual urine volume: ultrasonography Determining the Volume of Residual Urine by Ultrasonography (or single catheterization) after voiding
Interpreting the residual urine volume:
< 100 ml normal
> 200 ml requires further investigations
> 400 ml requires bladder catheterization (cystostomy, long-term catheterization or intermittent self-catheterization).
Difficulties with catheterization may suggest urethral stricture.