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Acute Urinary Retention

Last updated March 11, 2020

Approved by: Krish Tangella MD, MBA, FCAP

Acute Urinary Retention (AUR) is a condition characterized by the sudden inability to pass urine and completely empty the urinary bladder.

What are the other Names for this Condition? (Also known as/Synonyms)

  • AUR (Acute Urinary Retention)

What is Acute Urinary Retention? (Definition/Background Information)

  • Acute Urinary Retention (AUR) is a condition characterized by the sudden inability to pass urine and completely empty the urinary bladder. Individuals with Acute Urinary Retention are unable to urinate at all, even though the urinary bladder is filled with urine
  • The most common cause for AUR that generally affects men is benign prostatic hyperplasia (BPH), which is enlargement of the prostate. Other possible causes include urethral strictures, bladder/urethral stones, spinal cord injury, vaginal child birth, stroke, and the use of certain medications
  • The condition also results in abdominal pain and bloating. It may be diagnosed through abdominal and pelvic CT scans, cystoscopy, and urodynamic studies
  • Acute Urinary Retention is generally treated by bladder cauterization, to allow the flow of urine out of the body. Treatment of the underlying cause is necessary to prevent recurrence of the condition

Who gets Acute Urinary Retention? (Age and Sex Distribution)

  • Acute Urinary Retention can affect any individual of any age group, but it is more common in elderly adults
  • The condition is also more common in males than females, due to the fact that the urethra (tube connecting bladder to the exterior) is longer in males, and also because prostate enlargement, one of the important causative factors, is a common health problem in older males
  • AUR is seen worldwide with no racial or ethnic predilection being observed

What are the Risk Factors for Acute Urinary Retention? (Predisposing Factors)

The risk factors associated with Acute Urinary Retention include:

  • Elderly male: Due to an increased occurrence of benign prostatic enlargement in this age group
  • Elderly males with enlarged prostate
  • Urinary tract stones that may be found at the kidneys, ureters, or in the urinary bladder
  • Presence of cystocele in women; cystocele is the bulging of bladder into the vagina
  • Presence of rectocele in women; rectocele is the bulging of rectum into the vagina
  • Recurrent urinary tract infections that may cause urethral strictures
  • Individuals with diabetes
  • Injuries to the spinal cord

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Acute Urinary Retention? (Etiology)

  • Urine forms in the kidneys and then it passes through the ureters (tubes connecting the kidneys to the urinary bladder) to the urinary bladder. Urine gets stored in the urinary bladder and when it reaches a certain amount, an individual feels the urge to pass urine
  • The urethra is a small tube which connects the bladder to the outside of the body and is responsible for draining the urine out of the body. An Acute Urinary Retention (AUR) is a sudden inability to pass urine, despite a painful urge to urinate

Acute Urinary Retention can occur due to the following factors:

  • Urethral obstruction
  • Injuries to the nerves that control the urinary bladder
  • Certain medications
  • Weakened bladder muscles

Causes of urethral obstruction include:

  • Prostate enlargement in men
  • Stricture/scarring of the urethra due to a previous surgery, injury, or recurrent infection
  • Presence of stones/crystals in the urethra and bladder
  • Presence of cystocele in women (the bulging of bladder into the vagina, which may pinch the urethra)
  • Presence of rectocele in women (the bulging of rectum into the vagina, which may pinch the urethra)
  • Constipation
  • Bladder or urethral tumors

Causes of injuries to the nerves that control the urinary bladder include:

  • Spinal cord injury
  • Vaginal childbirth
  • Diabetes
  • Stroke


  • Amitriptyline
  • Amphetamines
  • Cetirizine
  • Chlorpheniramine
  • Diazepam
  • Diphenhydramine
  • Doxepin
  • Ephedrine
  • Fexofenadine
  • Hyoscyamine
  • Imipramine
  • Nortriptyline
  • Opioid analgesics
  • Oxybutynin
  • Phenylephrine
  • Pseudoephedrine
  • Toltoredine

Causes of weakened bladder muscles include:

  • Aging

Surgery: Under the effect of anesthesia, some individuals may experience temporary urinary retention.

What are the Signs and Symptoms of Acute Urinary Retention?

The signs and symptoms of Acute Urinary Retention may include:

  • Inability to pass urine despite a painful urge to urinate
  • Pain in the lower abdomen
  • Abdominal bloating

How is Acute Urinary Retention Diagnosed?

The following procedures may be used to diagnose Acute Urinary Retention:

  • Thorough evaluation of the individual’s medical history and a complete physical examination of the skin, heart, abdomen, rectum, and vagina
  • During history taking, the physician may want to know the following:
    • When the symptoms began and whether they are becoming worse
    • List of prescription and over-the-counter medications currently being taken
    • One’s personal and family history of kidney disease, stones, prostate-related problems, etc.        
  • The physical examination may reveal the following:
    • Enlarged bladder
    • Enlarged prostate
    • Mass (tumor) of the kidney, prostate, and cervix
    • Flank tenderness            
  • Urgent catheterization of the bladder is done for immediate relief. During this process, the diagnosis can also be confirmed

The following tests are generally carried out to assess the cause of Acute Urinary Retention:

  • Cystoscopy: It is the examination of the inside of the bladder with the help of a scope
  • Abdominal and pelvic CT scan
  • Urodynamic studies: These studies are performed to assess functioning of the bladder and urethra

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Acute Urinary Retention?

If Acute Urinary Retention is treated urgently, there are no long-term complications associated with it. However, if treatment is delayed, then the following may be observed:

  • Hypertension
  • Anxiety, sweating, and shock-like state
  • Long-term complications may include bladder stone formation, kidney failure, and urinary bladder damage

How is Acute Urinary Retention Treated?

The main goal for treatment is to promptly relieve the retention and ease the symptoms. The treatment options of Acute Urinary Retention include:

  • Bladder catheterization procedure (either through the urethra or abdomen) can be performed for immediate relief in case of BPH, bladder neck obstruction, or urethral stricture
  • Discontinuation of medication causing the condition
  • Definitive procedures to treat the underlying cause can be done at a later stage. These may include:
    • Trans urethral resection of prostate (TURP), which is the removal of prostate through the urethra
    • Urethral dilation and urethral stent placement to treat urethral stricture
    • Surgery to repair cystocele or rectocele
    • Appropriate treatment of the cancers responsible for causing the obstruction     

How can Acute Urinary Retention be Prevented?

Preventive measures of Acute Urinary Retention include:

  • Proper treatment of the underlying condition, before it gives rise to complications
  • In an individual with benign prostatic hyperplasia , certain medications can improve the flow of urine through an enlarged prostate and prevent Acute Urinary Retention
  • Elective treatment of individuals presenting with advanced BPH symptoms
  • Avoidance of certain medications responsible for causing AUR

What is the Prognosis of Acute Urinary Retention? (Outcomes/Resolutions)

  • The prognosis depends upon the underlying cause and duration of the condition
  • If Acute Urinary Retention is relieved or treated immediately, the kidneys resume their function uneventfully
  • Treatment of underlying cause is needed  to prevent recurrence of the condition

Additional and Relevant Useful Information for Acute Urinary Retention:

The following DoveMed website link is a useful resource for additional information:


What are some Useful Resources for Additional Information?

References and Information Sources used for the Article:

Helpful Peer-Reviewed Medical Articles:

Reviewed and Approved by a member of the DoveMed Editorial Board
First uploaded: July 24, 2015
Last updated: March 11, 2020