The organs of the urinary system include the kidneys, renal pelvis, ureters, bladder and urethra. The bladder acts as a reservoir holding the urine produced by the kidneys until the body pushes the urine out through the urethra when urinating. A muscular ring called a sphincter constricts to hold urine in the bladder and releases it when we need to urinate.
Urinary retention can be categorised as an acute or chronic (long-term) issue and form, and it can happen unexpectedly or worsen gradually with time. Chronic urinary retention involves the gradual increasing failure over time to empty the bladder of urine while urinating whereas acute urinary retention is characterised by the total inability to urinate, which occurs suddenly and is a medical emergency.
Although urinary retention is not a disease, it can be a symptom of other conditions, such as cystocele (also known as a fallen or prolapsed bladder) in people assigned female at birth (AFAB) or prostate issues in people assigned male at birth (AMAB).1 Urinary retention can cause incontinence (leakage of urine), the need to pee with increased frequency, and the urge to urinate again and repeatedly for a short duration after the previous urination.
Signs and symptoms of urinary retention
Acute urinary retention
Even if the bladder feels full and there is an intense need to urinate, often accompanied by pain and abdominal swelling, people with acute urine retention cannot pee.
Acute urinary retention symptoms include:
- The complete inability to pass urine,
- Intense lower abdominal pain
- A sudden, intense desire to urinate
- Lower abdominal swelling
Chronic urinary retention
Chronic urine retention develops gradually over time from months to years and is generally long-lasting. People who have this can urinate, but their bladders cannot empty urine – there is a residual volume of urine left in the bladder known as the postvoid residual urine volume (PVR). Because they might not feel any symptoms, many people who have chronic urinary retention are unaware that they have the problem.1
Chronic urinary retention symptoms include:
- Inability to empty the bladder when urinating
- Passing only small amounts of urine frequently
- Hesitancy, meaning difficulty starting the flow of urine
- An intense desire to urinate but with limited success
- A slow, sluggish urine stream
- Need to urinate again immediately after completing urination
- Urinating without warning or urge
Causes of urinary retention
This can be the result of a variety of causative conditions and factors including1,2,3
- Direct physical obstructions in the urinary tract, such as those caused by bladder stones, damage resulting in constriction of the urethra as a result of an accident or infection, or bladder cancer
- Prostate-related conditions in people AMAB such as benign prostatic hyperplasia (which is the most common obstructive cause, accounting for 53% of cases), prostatitis, or prostate cancer
- Cystocele in people AFAB, which causes the bladder to partially prolapse (droop) into the vagina, placing pressure on the bladder
- Extreme constipation that squeezes the urethra or bladder
- Pelvic floor issues caused by birth injuries or other physical traumas which reduce muscle strength or disrupt nerve function
- Infections and inflammatory conditions which can produce swelling of the urethra or bladder leading to acute urinary retention. In men (AMAB) these include acute bacterial prostatitis and balanitis – and in women, (AFAB) vulvovaginal candidiasis and Behçet syndrome
- Nerve damage that prevents the brain from communicating, or communicating correctly, with the urinary system. For example, after a spinal cord injury, for one to 12 months people can have spinal shock which produces chronic urinary retention. Other neurological conditions such as cauda equina, spinal stenosis, diabetes mellitus, Parkinson’s, multiple sclerosis and stroke are also causes of urinary retention.
- Many drugs, ranging from antihypertensives to antidepressants, antihistamines and decongestants have nervous system side effects, some causing an impact action of the detrusor muscle of the bladder that pushes urine out during urination
- Anaesthesia, which may for a while affect nerves and cause urinary retention after an operation
- Other causes include: post-surgery complications – in 2% to 14% of procedures, postoperative urine retention happens; urinary retention triggered by pregnancy – acute urine retention is more likely to occur both during pregnancy and after delivery; trauma– urinary retention may be a result of an acute injury to the urethra, penis, or bladder
Urinary retention can affect anyone, but it tends to rise in prevalence as individuals get older. People AMAB are generally more susceptible to urinary retention, due to prostate-associated problems and partial blockages of the urethra, than people AFAB.
Additionally, urinary tract infections, and the use of particular groups of medicines such as antihistamines, anticholinergics and some decongestants, are factors contributing to increased risk.
The process of pregnancy and giving birth can also increase the risk particularly if they result in trauma and injury to tissues.
Injury, inactivity and ageing can also cause weakening of the bladder muscles and nerve damage (including peripheral nerve damage from disorders such as diabetes) can be further contributing factors.
Diagnosis of urinary retention and its causes
To diagnose urinary retention, physicians will combine the findings from taking your medical history, from a physical examination, from testing and imaging, and from a postvoid residual urine measurement (PVR). The PVR uses either a catheter or ultrasound to measure the quantity of urine left remaining in the bladder after urination.3
The physical examination should include a comprehensive abdominal assessment involving feeling and percussion of the pelvic organs, bladder and flanks. In people AMAB there will be a rectal examination by the finger to assess the state of the prostate gland– checking for abnormal size, texture, and nodules– and checking for any rectal masses. In people AFAB a thorough pelvic examination should be included.
A general neurologic evaluation, as well as specific neurological tests related to bladder function, should also be conducted to detect or eliminate neurological (nervous system ) causes of urinary retention.
Lab tests may also be conducted by your physician to identify potential signs of diseases or conditions responsible for urinary retention:
- Urinalysis is employed to detect issues like urinary tract infections, kidney problems, and undiagnosed diabetes mellitus that might be causing urinary retention.
- Blood tests are used to assess kidney function, detect issues with the prostate and reveal any chemical imbalances within the body.
Imaging tests may include
- Ultrasound, which uses sound waves to create images, of the pelvis to detect masses, and of the kidneys and bladder to look for upper urinary tract diseases such as bladder and urethral stones
- The voiding cystourethrogram (VCUG) which utilizes X-rays to show the flow of urine through the bladder and urethra and can detect stones and restrictions to the flow of urine
- Magnetic resonance imaging (MRI) may be used to create pictures of the brain and spine to identify neurological problems producing urinary retention – including, in the brain: tumour, stroke and multiple sclerosis (MS); and in the spine: spinal tumours, spinal cord compression, lumbosacral disc herniation, cauda equina syndrome and MS
- Computed tomography (CT) scans are additional imaging methods that use magnets, radio waves, and X-rays combined with computer technology to produce detailed images of the urinary tract.
Urodynamic testing may also be used to help diagnose urinary retention. This is a set of tests used to evaluate how good the bladder, sphincters, and urethra are at storing and releasing urine.
- Uroflowmetry which measures the quantity and rate of urine released
- Pressure flow studies which monitor the pressure within the bladder and rate of urine flow during urination
- Video urodynamics which takes static and moving images of the bladder filling and emptying
- Cystometry which measures bladder capacity, the pressure development as the bladder is filled, and the pressure within the bladder when the onset of the urge to urinate occurs
- Electromyography which assesses how well the muscles in the bladder and sphincters respond to the nervous impulses they receive
Cystoscopy may also be used to visually inspect the inside of the urethra and bladder. A thin instrument called a cystoscope is inserted and the physician will carefully examine the areas for indications of swelling, redness, infection, cancer, and structural abnormalities.4
These tests collectively provide valuable information for diagnosing and understanding the causes of urinary retention.
Management and treatment of urinary retention
The type of urinary retention –acute or chronic– and its underlying cause determines the best course of action regarding treatment options. The following are some treatments that a doctor could suggest:3,4
- The use of a catheter to drain urine from the bladder. In acute retention, this will be carried out immediately to help prevent damage to the bladder and kidneys. In chronic retention that is unresponsive to initial treatments, a catheter may be inserted for a long period of time while the underlying problem is being worked out and resolved. Alternatively, the patient may be trained to insert and remove a catheter intermittently to fully drain the bladder
- Antibiotics to treat a urethral, prostatic or other infection
- Drugs to treat the medical cause, such as 5-alpha reductase inhibitors to stop the enlargement of the prostate or shrink it, and alpha blockers to decrease the symptoms caused by prostate enlargement by relaxing the muscles in the neck of the bladder and prostate, making urination easier
- Changing medication when the side effects of a prescription drug is to blame for retention
- Physiotherapy to help improve pelvic floor muscle strength and control and train better functioning of the bladder
- Cystoscopy to remove stones in the urethra and bladder
- Urethral dilation surgery to treat blocked or constricted urethras,
- Placement of a stent to prevent further blockages.
- Surgery to repair a cystocele and other pelvic organ prolapses
- Various methods to shrink or remove swollen prostate tissue, ranging from laser therapy to prostate surgery
Complications of urinary retention
Urinary tract infections (UTIs) can occur when bacteria enter the urinary tract and are not flushed out completely during urination. This can happen when there is urinary retention because the urine does not fully flow out. This allows the normally harmless bacteria present to multiply and cause an infection in the urinary tract. If the infection spreads to the kidneys, it can lead to serious problems.
If urinary retention is not treated, your bladder may become damaged from being stretched too far or for too long. When the bladder is stretched excessively or for prolonged periods, the muscles in the bladder can become damaged and no longer function correctly. Urinary retention can also result in kidney damage. Normally, urine flows from the kidneys through the ureters, into the bladder, and out through the urethra. When urinary retention occurs, the urine can back up into the kidneys. This can cause the kidneys to swell and put pressure on nearby organs. The increased pressure can result in kidney damage and, in some cases, may lead to chronic kidney disease and kidney failure.
Another consequence of incomplete bladder emptying is urinary incontinence. This can manifest as leakage of urine, known as overflow incontinence. Additionally, surgery to remove tumours or cancerous tissue in the bladder, prostate, or urethra may also result in urinary incontinence.
How can I prevent urinary retention?
To prevent urinary retention, you can:
- Drink plenty of fluids to stay hydrated and maintain urinary flow
- Empty your bladder regularly and fully
- Avoid delaying urination or holding in urine for long periods.
- Engage in regular exercise, eat a balanced diet with adequate fibre and drink fluids to remain hydrated thereby maintaining a healthy lifestyle and avoiding constipation which can be a cause of urinary retention
- Avoid alcohol and caffeine consumption
- Engage in pelvic floor muscle exercises which can help improve bowel and bladder function
How common is urinary retention?
Acute urinary retention is a condition that is more common in older men, and the chances of experiencing it increase with age. Over a period of five years, approximately 1 in 10 men over the age of 70 and nearly 1 in 3 men in their 80s will develop acute urinary retention. On the other hand, acute urinary retention is much less common in women, with about 3 in 100,000 women developing it each year. Acute urinary retention is rare in children.
When should I see a doctor?
You should see a doctor if you start experiencing symptoms of urinary retention such as:
- Difficulty initiating or maintaining urination
- Weak or interrupted urine flow
- Feeling a persistent need to urinate even after emptying the bladder
- Pain or discomfort during urination
- Frequent urinary tract infections
Urinary retention can be uncomfortable and unpleasant. It can be agonizing and quite frightening when it arises suddenly and prevents a person from urinating. Delay in seeking treatment could make the situation worse because acute, sudden urinary retention can be a medical emergency. There is no reason to be humiliated or embarrassed about urinary retention because generally, it is treatable. Frequently, a doctor can identify the issue underlying both chronic and acute urinary retention. To get additional testing and care, a person might need to be sent to a urologist, proctologist, or pelvic floor specialist.
- Kaplan, Steven A., et al. ‘Urinary Retention and Post-Void Residual Urine in Men: Separating Truth from Tradition’. The Journal of Urology, vol. 180, no. 1, July 2008, pp. 47–54. Available from: https://pubmed.ncbi.nlm.nih.gov/18485378/
- Serlin DC, Heidelbaugh JJ, Stoffel JT. Urinary retention in adults: evaluation and initial management. afp [Internet]. 2018 Oct 15 [cited 2023 Jun 1];98(8):496–503. Available from: https://www.aafp.org/pubs/afp/issues/2018/1015/p496.html
- Selius BA, Subedi R. Urinary retention in adults: diagnosis and initial management. afp [Internet]. 2008 Mar 1 [cited 2023 Jun 1];77(5):643–50. Available from: https://www.aafp.org/pubs/afp/issues/2008/0301/p643.html
- Rosenstein D, McAninch JW. Urologic emergencies. Med Clin North Am. 2004;88(2):495-518.Available from: https://pubmed.ncbi.nlm.nih.gov/15049590/