Benign prostatic hyperplasia
Overview
•Non-malignant enlargement of the prostate due to cellular proliferation (true hyperplasia, not hypertrophy) in the transition zone
•Affects ~40% of men in their 50s, up to ~90% by their 90s
•DHT (converted from testosterone by 5-alpha reductase) drives prostatic cell proliferation - explains mechanism of drug therapy
Presentation
LUTS symptom categories
| Category | Symptoms |
|---|---|
| Obstructive (voiding) | Poor stream, hesitancy, terminal dribbling, incomplete emptying, straining |
| Storage (irritative) | Urgency, frequency, nocturia, urgency incontinence |
| Post-micturition | Post-void dribble, sensation of incomplete emptying |
•IPSS (International Prostate Symptom Score): mild 0-7 / moderate 8-19 / severe 20-35 - guides treatment threshold
•DRE findings in BPH: smoothly enlarged, symmetrical, rubbery prostate; median sulcus may be obliterated - contrasts with hard/irregular/nodular prostate of cancer
Investigations
🥇 First-line
•
•IPSS questionnaire - quantify severity
•Urinalysis (+/- MSU) - exclude UTI, haematuria, glycosuria
•PSA - after informed discussion; do not test within 4 weeks of UTI, prostatitis, or DRE
•Frequency-volume chart (bladder diary) - differentiates LUTS from polyuria
•U&E - screen for obstructive uropathy/renal impairment
•Post-void residual (ultrasound) - >100 mL significant; >300 mL suggests chronic retention
•Second-line (secondary care):
•Uroflowmetry - Qmax >15 mL/s normal; Qmax <10 mL/s suggests obstruction (requires ≥150 mL voided)
•Transrectal/transabdominal ultrasound - prostate volume; guides choice of therapy
Differential diagnosis
•Prostate cancer - hard, irregular DRE; raised PSA; may lack LUTS early
•Overactive bladder - predominantly storage symptoms; normal prostate; no outflow obstruction
•Urethral stricture - history of catheterisation, gonorrhoea, or pelvic trauma; poor stream without prostate enlargement
•Prostatitis - fever, perineal pain, systemically unwell (acute); perineal discomfort, irritative LUTS (chronic)
•Bladder cancer - painless visible haematuria; urgent referral required
•Neurogenic bladder - LUTS in context of MS, Parkinson's, spinal cord pathology
Management
Step 1 · Mild symptoms (IPSS 0-7)
- 1Watchful waiting with lifestyle advice - reduce caffeine/alcohol, fluid timing, bladder training
- 2Review at 6-12 months with repeat IPSS, urinalysis, post-void residual
Step 2 · Moderate symptoms (IPSS 8-19)
- 1Alpha-blocker (alpha-1 adrenoceptor antagonist): tamsulosin 400 micrograms once daily - relaxes smooth muscle in prostate/bladder neck; rapid onset (days-weeks); review at 4-6 weeks
- 25-alpha reductase inhibitor: finasteride 5 mg once daily (or dutasteride 500 micrograms once daily) - reduces prostate volume; takes 3-6 months for effect; halves PSA (double PSA value for interpretation); reduces risk of AUR and progression
- 3Combination therapy (alpha-blocker + 5-ARI): preferred when prostate volume >30-40 mL or PSA >1.4 ng/mL - greater long-term benefit
Step 3 · Severe/refractory symptoms or complications
- 1Refer to urology for surgical management
Gold standard surgery
TURP (transurethral resection of the prostate) - risk of retrograde ejaculation ~75%, ED ~5-10%, incontinence
Alternatives
Laser prostatectomy (holmium/GreenLight), TUIP (smaller glands), open prostatectomy (very large glands)
Complications
•Acute urinary retention (AUR) - sudden inability to void; painful distended bladder; precipitated by constipation, UTI, anticholinergic drugs, excessive fluid intake, cold weather; requires immediate catheterisation and same-day urology review
•Chronic urinary retention - painless, large residual (often >300 mL); may present with overflow incontinence; risk of obstructive uropathy and renal failure
•Obstructive uropathy/hydronephrosis - bilateral back-pressure causing CKD; detected on renal ultrasound
•Recurrent UTIs - stagnant residual urine acts as culture medium
•Haematuria - due to engorged prostatic vasculature; always investigate to exclude malignancy before attributing to BPH