Urinary retention is an inability to effectively empty the bladder of urine. There are many possible causes of urinary retention in men, but the most common is due to enlargement of the prostate gland in older men (benign prostatic hyperplasia). Other causes include certain drugs, bladder stones, infections and cancer involving the urinary tract, trauma and surgery around the pelvis, and damage to the nerves supplying the bladder. Urinary retention can be acute, developing suddenly, or chronic, developing slowly over months and years.
Effects of Acute Urinary Retention
Urinary retention can develop suddenly with total inability to pass urine and swelling of the bladder with urine. Acute urinary retention causes severe pain and discomfort. It is considered a medical emergency because it can lead to rapid deterioration of kidney function as the pressure builds in the bladder and is transmitted back to the kidney. This can cause permanent damage to the kidney, leading to kidney failure. The sudden pressure buildup can damage the valve that controls the flow of urine into the bladder from the ureters (the two tubes that carry urine from the kidneys to the bladder).
Effects of Chronic Urinary Retention
Urinary retention developing slowly over time is called chronic urinary retention. Here, there is intermittent obstruction and occasional incomplete emptying. The pool of urine and the residual pressure in the bladder leads to several complications.
A residual pool of urine in the bladder encourages the growth of bacteria in the bladder. A bladder infection called cystitis can develop. Infection can also ascend up the ureters to the kidneys to cause kidney infections. Repeated kidney infections lead to scarring of the kidneys and the development of chronic renal failure.
Pressure of urine in the bladder can damage the control of the bladder and its muscular walls. The patient loses control of the bladder with dribbling of urine and incontinence. There is also a sense of urgency attached to the urge to urinate. Poor emptying of the bladder also increases frequency of urination. This can disrupt sleep at night. The dribbling of urine and incontinence negatively affects the social life of the patient.
In susceptible patients with retention caused by an obstruction (obstructive uropathy), straining to empty the bladder can predispose them to the development of hernias.
Treatment of Urinary Retention
The treatment of urinary retention is in two parts, namely the elimination of the retention and the treatment of the underlying cause. The elimination of the retention is achieved by catheterization, where a flexible rubber tube is inserted into the bladder to empty it. Treating the underlying cause to prevent reoccurrence of retention can be as simple as withdrawing an offending medication or more complex as a surgical intervention to remove an obstruction or repair a defect.
