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Acute and chronic urinary retention
Acute urinary retention is a painful inability to void with a full bladder; drain at once with a urethral catheter (or a suprapubic one when the urethra is blocked or injured), start an alpha-blocker, and attempt catheter removal after 2 to 3 days.
Why it matters in the exam
The exam shows an older man with an enlarged prostate who received an anticholinergic, an antihistamine, an opioid or decongestant drops, or who is after surgery and anaesthesia, and cannot void. The commonest cause in men is BPH; other causes: severe constipation, urethral stricture, clots, infection (prostatitis) and neurological disease. In a woman retention is rare and demands thinking of a neurological cause (multiple sclerosis, cauda equina compression), a pelvic mass, prolapse or drugs.
After drainage the volume is recorded — a volume over 1000 mL or chronic retention with hydronephrosis and a rising creatinine indicate high-pressure retention. Post-obstructive diuresis is defined as urine output above 200 mL per hour for 2 consecutive hours or above 3 litres in 24 hours; it is common when creatinine is high, and needs monitoring of blood pressure, fluids and electrolytes. Mild bleeding from the bladder after rapid drainage is common and transient, and gradual drainage is not needed.
An alpha-blocker (tamsulosin or alfuzosin) given for at least 2 to 3 days before catheter removal improves the chance of success. If the trial fails, the options are surgery to relieve obstruction (TURP or alternatives), clean intermittent self-catheterisation, or an indwelling or suprapubic catheter for a patient unfit for surgery. "Spontaneous" retention in BPH indicates more advanced disease than "precipitated" retention after a drug or surgery. Painless chronic retention sometimes presents as bedwetting in an older man.
Key points
- Immediate catheter drainage.
- Alpha-blocker before catheter removal.
- Post-obstructive diuresis: above 200 mL per hour for 2 hours.
- Suspected urethral injury — suprapubic catheter.
- Repeated failure — surgery or self-catheterisation.
Summary table
| Situation | Action | Note |
|---|---|---|
| Acute retention in a man | Urethral catheter and alpha-blocker | Removal trial after 2 to 3 days |
| Catheter fails or urethral injury suspected | Suprapubic catheter | Do not force a catheter |
| Chronic retention with rising creatinine | Drainage and urine output monitoring | Post-obstructive diuresis |
| Failed removal trial | TURP, self-catheterisation or indwelling catheter | According to the patient |
| Retention in a woman | Neurological and pelvic evaluation | Rare and needs a cause |
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Sources
- EAU Guidelines on Management of Non-neurogenic Male LUTS, 2025 edition — Acute urinary retention and conservative management
- AUA Guideline: Management of Lower Urinary Tract Symptoms Attributed to BPH, 2023 amendment — Acute urinary retention
- Campbell-Walsh-Wein Urology, 12th edition (2020) — Evaluation and Nonsurgical Management of Benign Prostatic Hyperplasia
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.