Benign Prostatic Hyperplasia
Age- and androgen-driven hyperplasia of the prostate's periurethral transitional zone that mechanically narrows the urethra, producing a predictable split between voiding and storage symptoms as the bladder first compensates and then fails.
In a nutshell
BPH grows in the transitional zone around the urethra, so even modest enlargement narrows the lumen. Obstruction produces voiding symptoms directly and storage symptoms indirectly, via compensatory detrusor hypertrophy. Alpha-blockers relax dynamic muscle tone; 5-alpha-reductase inhibitors shrink the static gland; surgery removes the obstruction when medical therapy fails.
Classic presentation
An older man with hesitancy, a poor stream and terminal dribbling alongside frequency, urgency and nocturia, and a smoothly enlarged prostate on examination.
Key points
- BPH arises in the transitional zone (surrounding the urethra); prostate cancer arises mainly in the peripheral zone. This explains their different symptom profiles.
- Voiding symptoms come from mechanical obstruction; storage symptoms come from the bladder's compensatory hypertrophy and irritability.
- Alpha-blockers act on dynamic smooth muscle tone (fast relief); 5-alpha-reductase inhibitors act on static gland bulk (slow shrinkage over months).
- Chronic retention can cause painless bladder distension and, if prolonged, back-pressure hydronephrosis and renal impairment.
- PSA is non-specific and raised by BPH, infection, retention and instrumentation, not only cancer, and needs counselling before testing.
- A hard, irregular or asymmetric prostate should prompt urgent cancer referral, not routine BPH management.
First-line investigation
Digital rectal examination plus urinalysis and flow rate/post-void residual assessment; PSA if appropriate after counselling.
First-line management
Lifestyle measures for mild symptoms, escalating to an alpha-blocker for moderate-to-severe symptoms.
Exam traps
- A markedly raised or rapidly rising PSA should not simply be attributed to BPH: it warrants further assessment for cancer.
- Do not delay catheterisation in acute retention while awaiting further work-up: decompress first.
- An irregular or asymmetric prostate on DRE is not typical BPH: treat as suspicious for malignancy.
- Chronic retention can be painless; a large distended bladder found incidentally still needs urgent management to protect renal function.
Educational content pending clinical review. Not medical advice.