Bladder outlet obstruction

Injury	Diseases	Nutrition	Poison
Symptoms	Surgery	Test	Special Topic

Female urinary tract

Kidney anatomy

Kidney - blood and urine flow

Definition

Bladder outlet obstruction (BOO) is a blockage at the base of the bladder that reduces or prevents the flow of urine into the urethra, the tube that carries urine out of the body.

Alternative Names

BOO; Lower urinary tract obstruction; Prostatism

Causes, incidence, and risk factors

Bladder outlet obstruction can have many different causes. Some of the most common causes of BOO are:

Benign prostatic hyperplasia (BPH)
Bladder calculi (stones)
Urethral stricture (scar tissue)
Bladder tumors (cancer)
Pelvic tumors (cervix, prostate, uterus, rectal)

Less common causes of bladder outlet obstruction include:

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Cystocele
Posterior urethral valves (congenital birth defect)
Foreign objects
Urethral spasms
Urethral diverticula

Bladder outlet obstruction is most common in aging men, and is often caused by BPH. Bladder stones and bladder cancer are also more commonly seen in men than women. As a man ages, the chance of developing these diseases increases dramatically. One in three American males over the age of 60 has significant symptoms of bladder outlet obstruction.

Review Date: 06/13/2006
Reviewed By: Neil D. Sherman, MD, Urologist, Essex County, NJ. Review provided by VeriMed Healthcare Network.