Urinary Retention

In women

Retention results from one or more of: reduced bladder contractility, poorly sustained detrusor contraction, inadequate anatomical outlet, deficient outlet relaxation, or impaired neurological coordination of voiding.

Acute retention: painful bladder distension, presents as an emergency; post-void residual often >250–300mL.

Chronic retention: typically non-painful bladder distension, risking overflow dribbling and impaired upper urinary tract function; post-void residual >250–300mL (normal ~50mL). May present as painful or painless inability to void, non-painful lower abdominal distension, or a weak stream. Ask about recurrent UTIs and incontinence.

Postpartum urinary retention is a common consequence of bladder dysfunction after vaginal delivery.

Risk factors: pelvic organ prolapse repair (including mini-sling procedures — see uterovaginal-prolapse.md), surgery for urinary incontinence (see incontinence-male-and-female.md), hysterectomy. Medications: opiates, antipsychotics, tricyclic antidepressants.

Examination

• Abdomen: acute retention may show a significantly distended bladder ± bilateral hydronephrosis — suprapubic fullness, abdominal/flank mass or pain
• Neuro: perineal sensation, sphincter tone, wink reflex
• Rectal: exclude faecal impaction or mass
• Pelvic: examine the urethra for obstructing mass/cyst/diverticulum; Valsalva to assess urethral hypermobility/stress incontinence; assess for prolapse; bimanual exam for uterine size/position and to exclude a mass

Investigations

UEC + urinalysis; bladder USS for post-void residual; consider urodynamic testing to differentiate detrusor underactivity from bladder outlet obstruction.

Management

Acute retention: refer to ED, catheterise, monitor for post-obstructive diuresis, assess for AKI.

Chronic retention:

• Conservative: timed/prompted voiding, pelvic floor exercises, withdraw causative medications, manage prolapse (manual reduction or other)
• Intermittent urethral catheterisation
• Consider an alpha-blocker (e.g. tamsulosin) to improve voiding dysfunction
• Refer to urology if the cause or management is unclear

In men

Usually spontaneous, related to longstanding BPH. Can be precipitated by surgery, pain, constipation, another obstructive process (bladder neck stenosis, urethral stricture), acute medical illness, a neurological condition, UTI, or medications.

Examination

Often a large palpable bladder. Examine genitalia to exclude phimosis/paraphimosis (see phimosis-paraphimosis.md); DRE if BPH history is unknown; neurological exam if a neurological cause or recent trauma is suspected.

Investigations

Urine MC&S; UEC for AKI.

Management

Send to ED — insert a transurethral catheter (collect a sample for pathology), monitor renal function, start an alpha-blocker (e.g. tamsulosin 400mcg daily). If BPH-related, keep the catheter indwelling for 3 days with urology follow-up.

For elective (non-emergency) BPH/LUTS management options beyond alpha-blockers — including newer minimally invasive procedures (UroLift, Rezum, prostatic artery embolisation) that can avoid TURP’s sexual-function side effects — see mens-health’s benign-prostatic-hypertrophy.md.