Lima Memorial Health System Logo
Approximate ER WAIT TIME WAIT TIME MACRO
Lima Memorial eHealth
Careers
Ways to Give

Health Library

Bladder outlet obstruction
     
Print-Friendly
Bookmarks

Bladder outlet obstruction

BOO; Lower urinary tract obstruction; Prostatism; Urinary retention - BOO

 

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

Causes

 

This condition is common in aging men. It is often caused by an enlarged prostate. Bladder stones and bladder cancer are also more commonly seen in men than women. As a man ages, the chances of getting these diseases increase greatly.

Other common causes of BOO include:

  • Pelvic tumors (cervix, prostate, uterus, rectum)
  • Narrowing of the tube that carries urine out of the body from the bladder (urethra), due to scar tissue or certain birth defects

Less common causes include:

  • Cystocele (when the bladder falls into the vagina)
  • Foreign objects in the bladder or urethra
  • Urethral or pelvic muscle spasms
  • Inguinal (groin) hernia

 

Symptoms

 

The symptoms of BOO may vary, but can include:

  • Abdominal pain
  • Continuous feeling of a full bladder
  • Frequent urination
  • Pain during urination (dysuria)
  • Problems starting urination (urinary hesitancy)
  • Slow, uneven urine flow, at times being unable to urinate
  • Straining to urinate
  • Urinary tract infection
  • Waking up at night to urinate (nocturia)
  • Urinary incontinence

 

Exams and Tests

 

Your health care provider will ask about your symptoms and medical history. You will undergo a physical exam.

One or more of the following problems may be found:

  • Abdominal swelling
  • Cystocele (women)
  • Enlarged bladder
  • Enlarged prostate (men)

Tests may include:

  • Blood chemistries to look for signs of kidney damage
  • Cystoscopy and retrograde urethrogram (x-ray) to look for narrowing of the urethra
  • Tests to determine how fast urine flows out of the body (uroflowmetry)
  • Tests to see how much the urine flow is blocked and how well the bladder contracts (urodynamic testing)
  • Ultrasound to locate the blockage of urine and find out how well the bladder empties
  • Urinalysis to look for blood or signs of infection in the urine
  • Urine culture to check for an infection

 

Treatment

 

Treatment of BOO depends on its cause. A tube, called a catheter, is inserted into the bladder through the urethra. This is done to relieve the blockage.

Sometimes, a catheter is placed through the belly area into the bladder to drain the bladder. This is called a suprapubic tube.

Most often, you will need surgery for a long-term cure of BOO. However, many of the diseases that cause this problem can be treated with medicines. Talk to your provider about possible treatments.

 

Outlook (Prognosis)

 

Most causes of BOO can be cured if diagnosed early. However, if the diagnosis or treatment is delayed, this can cause permanent damage to the bladder or kidneys.

 

When to Contact a Medical Professional

 

Contact your provider if you have symptoms of BOO.

 

 

Open References

References

Capogrosso P, Pozzi E, Salonia A, Montorsi F. Evaluation and nonsurgical management of benign prostatic hyperplasia. In: Dmochowski RR, Kavoussi LR, Peters CA, et al, eds. Campbell-Walsh-Wein Urology. 13th ed. Philadelphia, PA: Elsevier; 2026:chap 150.

Cruz F, Michel MC, Igawa Y. Pharmacologic management of lower urinary tract storage and emptying failure. In: Dmochowski RR, Kavoussi LR, Peters CA, et al, eds. Campbell-Walsh-Wein Urology. 13th ed. Philadelphia, PA: Elsevier; 2026:chap 113.

Heesakkers JPFA, Smits M, van Koeveringe G. Electrical stimulation and neuromodulation in storage and emptying failure. In: Dmochowski RR, Kavoussi LR, Peters CA, et al. eds. Campbell-Walsh-Wein Urology. 13th ed. Philadelphia, PA: Elsevier; 2026:chap 115.

Kaplan SA. Benign prostatic hyperplasia and prostatitis. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 114.

BACK TO TOPText only

 
  • Kidney anatomy

    Kidney anatomy

    illustration

  • Female urinary tract

    Female urinary tract

    illustration

  • Male urinary tract

    Male urinary tract

    illustration

  • Kidney - blood and urine flow

    Kidney - blood and urine flow

    illustration

    • Kidney anatomy

      Kidney anatomy

      illustration

    • Female urinary tract

      Female urinary tract

      illustration

    • Male urinary tract

      Male urinary tract

      illustration

    • Kidney - blood and urine flow

      Kidney - blood and urine flow

      illustration

    A Closer Look

     

    Talking to your MD

     

      Self Care

       

        Tests for Bladder outlet obstruction

         
         

        Review Date: 4/19/2026

        Reviewed By: Kelly L. Stratton, MD, FACS, Associate Professor, Department of Urology, University of Oklahoma Health Sciences Center, Oklahoma City, OK. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

        The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. No warranty of any kind, either expressed or implied, is made as to the accuracy, reliability, timeliness, or correctness of any translations made by a third-party service of the information provided herein into any other language.

        © 1997- A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

        All content on this site including text, images, graphics, audio, video, data, metadata, and compilations is protected by copyright and other intellectual property laws. You may view the content for personal, noncommercial use. Any other use requires prior written consent from Ebix. You may not copy, reproduce, distribute, transmit, display, publish, reverse-engineer, adapt, modify, store beyond ordinary browser caching, index, mine, scrape, or create derivative works from this content. You may not use automated tools to access or extract content, including to create embeddings, vectors, datasets, or indexes for retrieval systems. Use of any content for training, fine-tuning, calibrating, testing, evaluating, or improving AI systems of any kind is prohibited without express written consent. This includes large language models, machine learning models, neural networks, generative systems, retrieval-augmented systems, and any software that ingests content to produce outputs. Any unauthorized use of the content including AI-related use is a violation of our rights and may result in legal action, damages, and statutory penalties to the fullest extent permitted by law. Ebix reserves the right to enforce its rights through legal, technological, and contractual measures.
        © 1997- adam.comAll rights reserved.