Incapacity to empty the bladder or difficulty in doing so. Urinary retention can be complete (in which urine cannot be passed voluntarily at all) or incomplete (in which the bladder fails to empty completely).
In men, causes of urinary retention include phimosis (tight foreskin), prostatitis (inflammation of the prostate gland), urethral stricture (narrowing of the urethra), a stone in the bladder, and tumour or enlargement of the prostate. In females, causes include pressure on the urethra from uterine fibroids or from a growing fetus in the uterus. In either sex, the cause can be a bladder tumour.
Urinary retention can also be caused by a defective functioning of the nerve pathways that supply the bladder as a result of general or spinal anaesthesia, of drugs affecting the bladder, of surgery, of injury to the nerves, or of disease to the spinal cord.
Complete urinary retention causes lower abdominal pain (except when the nerve pathways are defective) and discomfort. The full bladder can be felt above the pubic bone. Chronic or partial urinary retention, however, may not cause any problems, and the affected person may be unaware of the condition. Urinary retention can lead to kidney damage and a urinary tract infection.
The condition is treated with by catheterisation. The cause is the investigated. Obstruction can often be treated; if nerve damage is the cause, intermittent or permanent catheterisation is occasionally needed.