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See also separate articles Benign Prostatic Hyperplasia, Urinary Tract Obstruction, Lower Urinary Tract Symptoms in Men, Lower Urinary Tract Symptoms in Women, Voiding Difficulties and Acute Urinary Retention. Urinary retention is the inability to empty the bladder. Chronic urinary retention is frequently asymptomatic - a patient is able to urinate, but may experience lower urinary tract symptoms (LUTS), related to storage and voiding difficulties. This is in contrast to acute urinary retention, a medical emergency, which is painful and the patient is unable to urinate despite a full bladder. Chronic urinary retention, whilst not immediately life-threatening, can lead to hydronephrosis and renal impairment and puts the patient at risk of acute-on-chronic retention, so requires diagnosis and treatment.
The most usual cause of chronic urinary retention is bladder outlet obstruction.
Important causes of bladder outlet obstruction:
- Benign prostatic hyperplasia (BPH) is by far the most common cause and is a common sequelae of male ageing.
- Prostatic carcinoma can obstruct the urethra either by a direct mass effect (as in BPH) or by invasion of the wall.
- Drugs causing bladder sphincter dysfunction include:
- Iatrogenic, eg following colposuspension.
- Congenital deformities:
- Urethral strictures resulting from:
- This is largely a condition that affects men, as its most common cause is benign prostatic hyperplasia (BPH), but there is an appreciable background incidence in women.
- Experience of urinary storage or of voiding-related symptoms is very common in middle-aged to older men. However, as they increase in severity, they have a significantly negative effect on quality of life. Over 40% of men aged 50 years or more have moderate-to-severe LUTS but many do not seek medical help and simply put up with the problem. Only 18% have a diagnosis of BPH.
- The cause of urinary retention in women is unknown in about a third of cases but approximately half are due to Fowler's syndrome (typically seen in women in their 20s-30s and thought to be due to failure of the urethral sphincter to relax appropriately).
The symptoms, if any are present, usually come on slowly and may not be noticed due to their gradual evolution. The more common ones are listed below:
- Urinary frequency.
- Urinary urgency.
- Urinary hesitancy.
- Poor urinary stream.
- Post-micturition dribbling.
- New-onset enuresis.
- Urinary incontinence.
- A sensation of incomplete voiding after micturition.
- 'Double' or recurrent voiding of urine (returning to micturition due to a sensation of 'needing to go again').
- Symptoms consistent with urinary tract infection.
- Increasing lower abdominal discomfort (may indicate intermittent acute-on-chronic-retention).
- Acute urinary retention.
- Lethargy, pruritus, recurrent infections, hypertension due to renal failure (rare with cases of mild-to-moderate obstructive uropathy).
- Check blood pressure as a possible indicator of renal impairment.
- Abdominal and genitourinary examination:
- Patients with long-standing significant urinary retention may have a palpable enlarged bladder, which will usually be non-tender.
- Check for enlargement of kidneys, via bimanual palpation.
- Digital rectal examination should be carried out to look for evidence of prostatomegaly and any signs of prostatic carcinoma.
- Examine external genitalia in children, men and women to seek evidence of urethral abnormalities causing urinary flow obstruction, eg urethral stricture, phimosis, meatal stenosis.
- Neurological examination should exclude cord compression and look for evidence of other relevant neurological conditions.
A vast range of conditions can cause chronic urinary retention, most commonly via preventing bladder outflow (see above). Additional causes of impaired emptying of the bladder are due to dysfunction of the bladder muscle or its innervation.
- Urinalysis - look for evidence of glycosuria, infection, proteinuria or haematuria.
- MSU for urine microscopy and culture.
- Blood tests:
- U&Es/creatinine to seek evidence of renal failure. They can be normal even in significant renal impairment, so consider using estimated GFR calculator (abbreviated MDRD calculation - MDRD = Modification of Diet in Renal Disease Study) or checking creatinine clearance by 24-hour urinary collection.
- FBC to exclude anaemia of chronic renal failure or raised white cell count due to infection.
- Blood glucose should be checked if diabetes may be causing an osmotic diuresis and thus leading to lower urinary tract symptoms (LUTS).
- Prostate specific antigen (PSA) should be considered in patients aged >70 years or where there is a clinical suspicion of prostate cancer after digital rectal examination/on the basis of symptoms such as backache. There is controversy over PSA's usefulness as a screening investigation, and current consensual best practice is to counsel anyone having the test as to the potential consequences of an abnormal result, and current uncertainties about optimal management in the case of an abnormal result. For asymptomatic individuals or those with uncomplicated LUTS, it is acceptable to omit PSA testing.
- Voiding diaries.
- Many further investigations may be used in secondary care to investigate the severity of urinary flow disruption and to establish the underlying cause. These include:
- Urinary tract ultrasound (including prostatic ultrasound performed transrectally ± prostatic biopsy).
- MRI or CT imaging of the urinary tract.
- Post-voiding residual volume determination through catheterisation (the definition of significant post-void residual urine remains debatable).
- Urodynamic studies (uroflowmetry, cystometry).
- Intravenous pyelography ± post-voiding imaging of residual urine volume.
- Renal radionuclide scanning.
- A useful way of classifying the severity of patient symptoms (and deciding on the degree of intervention necessary to improve them) is use of the International Prostate Symptom Score (IPSS).
- It is a well-validated measure of symptom severity but does not necessarily correlate with the severity of the causative pathology (particularly for benign prostatic hyperplasia (BPH)).
- Response to the quality-of-life question in the IPSS ('If you were to spend the rest of your life with your urinary condition the way it is now, how would you feel about that?') is a strong predictor for determining if interventions are indicated.
All patients should be referred to specialists.
- Check renal function and image the urinary tract.
- If these are abnormal or normal but lower urinary tract symptoms (LUTS) are present, consider the following:
- Intermittent self-catheterisation if possible; if not, long-term catheterisation may need to be considered.
- This should be followed by treatment of the underlying cause, eg with surgery.
- If surgery is not an option than ongoing self-catheterisation or a permanent catheter may be necessary.
- If the renal function and imaging are normal and the patient is asymptomatic:
- Catheterisation, as above.
- If the patient is not catheterised than actively monitor them, eg post-void residual volume measurements and upper tract imaging.
Other general measures
- Stop any precipitating/aggravating medication.
- General lifestyle advice such as:
- Regulating fluid intake and avoiding evening drinking.
- Reducing alcohol intake.
- Reducing tea and coffee intake.
- Preparation enabling access to toileting facilities.
- Use of bladder retraining and regular voiding.
- Drug therapy:
These may provide symptom improvement until more definitive measures can be undertaken (if this a possibility).
- Alpha-blockers, such as tamsulosin. Note: there is very limited evidence of significant 'real-world' effectiveness for their use in primary care.
- 5-alpha-reductase inhibitors, such as finasteride, to prevent progression of symptoms due to prostatic hyperplasia.
- Combination therapy with alpha-blockers and 5-alpha-reductase inhibitors reduces the likelihood of acute urinary retention or progression to the need for surgery in cases of BPH in a 'real-life' setting.
- Saw palmetto extract (phytotherapy with Serenoa repens) appears to be comparably effective to tamsulosin.
- Acute retention of urine.
- Hypertrophy of detrusor muscle and formation of diverticula.
- Hydronephrosis due to chronic back pressure on kidneys, ultimately resulting in renal impairment.
- Urinary incontinence due to overflow.
This is highly variable depending on the underlying cause.
In benign prostatic hyperplasia (BPH), the general trend is for symptoms to worsen over time. However, there is considerable variability and some patients experience permanent or transient improvement. Only about 14% of men with moderate-to-severe symptoms had clinically noticeable worsening of their symptoms during five years of follow-up. In one large trial of men with BPH and moderate-to-severe baseline symptoms, only 6% of men on placebo experienced acute urinary retention or needed BPH surgery after five years and none developed renal insufficiency.
Further reading & references
- Prostate - benign hyperplasia, Clinical Knowledge Summaries (August 2010)
- Verhamme KM, Sturkenboom MC, Stricker BH, et al; Drug-induced urinary retention: incidence, management and prevention. Drug Saf. 2008;31(5):373-88.
- Shaban AM, Drake MJ; Botulinum toxin treatment for overactive bladder: risk of urinary retention. Curr Urol Rep. 2008 Nov;9(6):445-51.
- Wilt TJ, N'Dow J; Benign prostatic hyperplasia. Part 1--diagnosis. BMJ. 2008 Jan 19;336(7636):146-9.
- Kavia RB, Datta SN, Dasgupta R, et al; Urinary retention in women: its causes and management. BJU Int. 2006 Feb;97(2):281-7.
- Yoshimura N, Chancellor MB; Differential diagnosis and treatment of impaired bladder emptying. Rev Urol. 2004;6 Suppl 1:S24-31.
- Amling CL; Prostate-specific antigen and detection of prostate cancer: What have we learned and what should we recommend for screening? Curr Treat Options Oncol. 2006 Sep;7(5):337-45.
- Lower Urinary Tract Symptoms in the Male, NHS Scotland Centre for Change and Innovation, Patient Pathway, July 2005; Clinical investigation and management pathway
- The management of lower urinary tract symptoms in men; NICE Clinical Guideline (May 2010)
- Kaplan SA, Wein AJ, Staskin DR, et al; Urinary retention and post-void residual urine in men: separating truth from tradition. J Urol. 2008 Jul;180(1):47-54. Epub 2008 May 15.
- Franciosi M, Koff WJ, Rhoden EL; Correlation between the total volume, transitional zone volume of the prostate, transitional prostate zone index and lower urinary tract symptoms (LUTS). Int Urol Nephrol. 2007 Jan 4;.
- Norg RJ, van de Beek K, Portegijs PJ, et al; The effectiveness of a treatment protocol for male lower urinary tract symptoms in general practice: a practical randomised controlled trial. Br J Gen Pract. 2006 Dec;56(533):938-44.
- Roehrborn CG; 5-alpha-Reductase Inhibitors Prevent the Progression of Benign Prostatic Hyperplasia. Rev Urol. 2003;5 Suppl 5:S12-21.
- Kim CI, Chang HS, Kim BK, et al; Long-term results of medical treatment in benign prostatic hyperplasia. Urology. 2006 Nov;68(5):1015-9. Epub 2006 Nov 7.
- Hizli F, Uygur MC; A prospective study of the efficacy of Serenoa repens, Tamsulosin, and Serenoa repens plus Tamsulosin treatment for patients with benign prostate hyperplasia. Int Urol Nephrol. 2007 Jan 4;.
- McConnell JD, Roehrborn CG, Bautista OM, et al; The long-term effect of doxazosin, finasteride, and combination therapy on the clinical progression of benign prostatic hyperplasia. N Engl J Med. 2003 Dec 18;349(25):2387-98.
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Dr Sean Kavanagh, Dr Chloe Borton
Dr Gurvinder Rull
Dr Adrian Bonsall