Benign Prostatic Hyperplasia (BPH): Causes, Symptoms and Treatment

Benign Prostatic Hyperplasia (BPH): Causes, Symptoms and Treatment

Benign prostatic hyperplasia (BPH) — commonly called an enlarged prostate — is the non-cancerous proliferation of prostate glandular and stromal tissue that causes bladder outlet obstruction and lower urinary tract symptoms (LUTS). It is the most common urological condition in ageing men: more than 50% of men have histological BPH by age 60, rising to over 90% by age 85. While not all men with BPH develop significant symptoms, approximately 25–30% of men over 50 have LUTS severe enough to affect quality of life.

BPH is distinct from prostate cancer — it is a benign condition with no malignant potential. However, prolonged severe obstruction can lead to chronic urinary retention, recurrent urinary tract infections, bladder diverticula, bladder stones, and ultimately obstructive nephropathy and renal impairment if left untreated.

Anatomy and How BPH Causes Obstruction

The prostate gland surrounds the urethra at the base of the bladder. It is divided into zones: the transition zone — immediately surrounding the urethra — is the site of BPH; the peripheral zone is where prostate cancer predominantly arises.

As BPH develops, the transition zone enlarges progressively, compressing the urethra — narrowing and lengthening it, increasing urethral resistance, and forcing the bladder detrusor muscle to work harder to expel urine. Over years:

1. Detrusor hypertrophy — the bladder muscle thickens and becomes overactive (causing urgency and frequency) to overcome resistance
2. Detrusor decompensation — with prolonged obstruction, the bladder muscle weakens, causing incomplete emptying and post-void residual urine accumulation
3. Bladder trabeculation and diverticula — chronic high-pressure voiding causes structural bladder changes
4. Obstructive nephropathy — in severe cases, high bladder pressures cause hydroureter and hydronephrosis, threatening renal function

Why Does BPH Develop?

The exact cause is multifactorial, but two factors are essential:

• Ageing — BPH becomes more common with increasing age
• Androgens — specifically dihydrotestosterone (DHT), the active metabolite of testosterone formed by the enzyme 5-alpha reductase type 2 within prostate cells; DHT drives prostate cell proliferation. This is why 5-alpha reductase inhibitors (5-ARIs) effectively reduce prostate volume.

Additional risk factors:

• Family history (first-degree relative with BPH — significantly increased risk)
• Obesity and metabolic syndrome — insulin resistance and elevated IGF-1 promote prostate cell growth
• Diabetes mellitus — insulin-like effects
• Cardiovascular disease — shared pathophysiology with metabolic syndrome

Oestrogen may also play a role in BPH development — as testosterone declines with age, the oestrogen:testosterone ratio rises, potentially sensitising prostatic stroma to androgen stimulation.

Symptoms — Lower Urinary Tract Symptoms (LUTS)

BPH-related LUTS are classified into two groups:

Storage (Irritative) Symptoms

Caused by detrusor overactivity and bladder hypersensitivity:

• Urinary urgency — sudden compelling desire to void that is difficult to defer
• Frequency — voiding more than 8 times in 24 hours
• Nocturia — waking to pass urine during the main sleep period, even once; repeated episodes can disrupt sleep
• Urge incontinence — involuntary urine leakage associated with urgency

Voiding (Obstructive) Symptoms

Caused by urethral obstruction:

• Hesitancy — difficulty initiating urination; prolonged wait before flow begins
• Weak stream — reduced urinary flow rate (normal >15 mL/s; obstructed often <10 mL/s)
• Intermittency — urine flow that stops and starts during voiding
• Straining — needing to push or strain to initiate or maintain voiding
• Terminal dribbling — prolonged dribbling at the end of urination
• Incomplete emptying — sensation of incomplete bladder emptying; significant post-void residual

Post-micturition Symptoms

• Post-void dribbling — involuntary loss of urine immediately after completing voiding

Complications of Severe BPH

• Acute urinary retention (AUR) — sudden complete inability to void; painful; requires emergency urethral catheterisation; occurs in approximately 2–3% of men with symptomatic BPH per year; can be precipitated by anticholinergic drugs, alcohol, dehydration, or prostatic infection
• Chronic urinary retention — painless, progressive inability to empty the bladder; large post-void residuals (>300–500 mL); risk of overflow incontinence, recurrent UTI, and obstructive nephropathy
• Recurrent UTI — residual urine is a culture medium for bacteria
• Bladder stones — urinary stasis leads to crystallisation
• Haematuria — blood in the urine can occur with BPH, but it needs assessment for other causes rather than being assumed to come from the prostate.

IPSS Score

The International Prostate Symptom Score (IPSS) is the validated symptom questionnaire used universally to quantify LUTS severity and guide treatment decisions:

• 0–7: Mild symptoms
• 8–19: Moderate symptoms
• 20–35: Severe symptoms
• Plus quality-of-life question (0–6)

The score records symptom severity; it does not determine treatment by itself. Bother, complications, examination findings, preferences and response to previous treatment also matter.

Diagnosis

Digital Rectal Examination (DRE)

Assessment of prostate size, consistency, and symmetry. BPH produces a smooth, symmetrical, firm, rubbery enlargement. Nodularity or firmness should prompt consideration of prostate cancer.

PSA (Prostate-Specific Antigen)

Serum PSA is routinely measured in men with LUTS — elevated PSA may reflect large prostate volume (BPH raises PSA proportionally to volume), prostatitis, or prostate cancer. PSA density (PSA divided by prostate volume) and age-specific PSA ranges help distinguish BPH from cancer.

PSA in BPH also serves as a predictor of BPH progression — PSA >1.5 ng/mL predicts higher risk of AUR and surgical need, informing decision to use 5-alpha reductase inhibitors.

Uroflowmetry

Non-invasive measurement of urine flow rate and pattern during voiding. Obstruction reduces maximum flow rate (Qmax) below 10–15 mL/s and may show a prolonged, plateau-shaped flow curve. Voided volume must be >150 mL for reliable interpretation.

Post-Void Residual (PVR) Measurement

Bladder ultrasound immediately after voiding measures residual urine volume. PVR >100–150 mL indicates incomplete emptying; PVR >300 mL suggests significant retention and increases complication risk.

Prostate Volume Assessment

Transrectal ultrasound (TRUS) or abdominal ultrasound accurately measures prostate volume. Volume informs, but does not determine, treatment. Alpha-blockers address symptoms; 5-ARIs are considered with enlargement and progression risk. Large prostates may favour an enucleation technique, depending on anatomy, symptoms and local expertise. A size threshold alone does not mandate medicine or surgery.

Urodynamics (Pressure-Flow Studies)

Pressure-flow studies measure bladder pressure and urinary flow to help distinguish bladder outlet obstruction from detrusor underactivity. They are not routinely required before every prostate operation. A specialist selects testing when diagnostic uncertainty or the individual history makes the result relevant to treatment choice. Previous pelvic surgery calls for appropriate specialist assessment rather than an automatic requirement for the same test in every patient.

Cystoscopy

Endoscopic inspection of the urethra, prostate, and bladder under local or general anaesthesia. Directly visualises prostatic lobar anatomy, urethral calibre, bladder neck, bladder trabeculation, diverticula, and stones; used when findings may change the diagnosis or choice of procedure.

Renal Ultrasound and Creatinine

In men with large PVR or suspected obstructive nephropathy — to assess upper tract dilatation and renal function.

Treatment

Treatment is guided by IPSS severity, prostate volume, PSA, uroflowmetry, PVR, and quality of life impact.

Watchful Waiting

For mild LUTS (IPSS 0–7) with no complications — monitoring with annual reassessment. Lifestyle advice:

• Fluid management — reduce evening fluid intake; avoid caffeine and alcohol
• Bladder training — urge suppression techniques
• Double voiding — a second void 5–10 minutes after the first
• Review medicines with your clinician, including diuretics and medicines with anticholinergic effects. Some can worsen urinary symptoms, but some are deliberately prescribed for selected urinary problems. Do not stop or change prescribed medicines without advice.

Alpha-Blockers (α1-Adrenergic Receptor Antagonists)

First-line pharmacological treatment for moderate-to-severe LUTS regardless of prostate size. Relax smooth muscle in the prostate, bladder neck, and urethra — rapidly reducing outflow resistance.

Examples: tamsulosin (selective α1A), silodosin (highly selective α1A), alfuzosin, doxazosin (also treats hypertension)

• Onset of action: 1–2 weeks; full effect by 4–6 weeks
• Reduce IPSS by approximately 30–40%; improve Qmax by 15–30%
• Side effects: postural hypotension (particularly non-selective agents), dizziness, ejaculatory changes, including reduced or absent semen (particularly with tamsulosin or silodosin). Medication-related changes are not necessarily permanent and usually improve after the responsible medicine is stopped under medical advice; discuss fertility concerns before changing treatment
• Do not reduce prostate volume or prevent disease progression

5-Alpha Reductase Inhibitors (5-ARIs)

Block conversion of testosterone to DHT within the prostate — gradually reduce prostate volume by 20–25% over 6–12 months. Indicated for men with large prostates (>30–40 mL by volume or PSA >1.5 ng/mL as a proxy).

Examples: finasteride (5 mg daily), dutasteride (0.5 mg daily — blocks both type 1 and 2 isoenzymes)

• Take 6–12 months for full effect
• In the four-year PLESS trial, finasteride reduced the relative risk of AUR by 57% and BPH-related surgery by 55% versus placebo in men with enlarged prostates and moderate-to-severe symptoms. These are trial results, not a guarantee for an individual.
• Side effects: sexual dysfunction (erectile dysfunction, reduced libido, reduced ejaculation volume) and gynaecomastia; frequency varies by medicine and duration of treatment. These medicines can reduce PSA by approximately 50%. Tell the clinician interpreting the PSA that you take a 5-ARI; interpretation depends on treatment duration and the PSA trend.
• Combination alpha-blocker + 5-ARI can improve symptoms in selected men with enlarged prostates: CombAT studied tamsulosin + dutasteride, whereas MTOPS studied doxazosin + finasteride. A clinician may consider withdrawing the alpha-blocker after a period of successful combination therapy; severe symptoms may require longer treatment. Do not stop it on your own

PDE5 Inhibitors

Tadalafil 5 mg once daily has a US-approved indication for the signs and symptoms of BPH, including when erectile dysfunction coexists. It can improve symptoms, but a consistent improvement in maximum urinary flow should not be assumed. Local approval, suitability and interactions must be checked by the prescriber; it must not be combined with nitrates.

Anticholinergics / Beta-3 Agonists

For persistent storage symptoms despite an alpha-blocker, a clinician may consider additional treatment after reassessing the symptoms and bladder emptying. Antimuscarinic medicines such as solifenacin or tolterodine can increase residual urine and retention risk: the EAU guideline advises against their use in men with a post-void residual above 150 mL. Residual urine and symptoms require monitoring. Mirabegron is a beta-3 agonist with different precautions; assess blood pressure and the product-specific restrictions rather than applying the antimuscarinic threshold to it. UK safety guidance contraindicates mirabegron in severe uncontrolled hypertension. These are prescribing decisions, not medicines to start or add independently.

Surgical Treatment

Surgery may be needed for persistent troublesome symptoms despite other treatment, recurrent or refractory retention, recurrent infection, bladder stones or obstruction-related renal impairment. An initial retention episode requires prompt drainage and reassessment; it does not automatically mean surgery. An elevated post-void residual alone is not a surgical indication.

Transurethral Resection of the Prostate (TURP)

The gold standard surgical procedure for prostates 30–80 mL. A resectoscope is passed through the urethra; the obstructing transition zone is resected using electrocautery (monopolar or bipolar) chip by chip. The standard surgical reference procedure against which all others are compared.

• A meta-analysis of 20 randomised trials cited by EAU found an average IPSS reduction of about 70% after monopolar TURP, with improved maximum urinary flow; individual results vary
• Day-case or 1–2 night inpatient
• Retrograde ejaculation is common after TURP and may be lasting; it can affect fertility even when orgasm remains possible. Discuss this before surgery.
• Bipolar TURP (saline irrigation) has lower risk of TUR syndrome (dilutional hyponatraemia) than monopolar
• Risk of erectile dysfunction approximately 5–10%; urinary incontinence approximately 1–2%

Transurethral Enucleation (HoLEP / ThuLEP / BipolEP)

Holmium laser enucleation of the prostate (HoLEP) — the preferred technique for large prostates (>80 mL) and increasingly for standard-sized prostates; enucleates the adenoma in anatomical planes using a holmium laser, then morcellates the tissue. ThuLEP is the corresponding thulium laser enucleation technique. Advantage: size-independent, high efficacy, durable outcomes, lower haemorrhage risk, shorter catheterisation time. Requires expert laser training; standard at high-volume centres.

Open/Robotic Simple Prostatectomy

For large to very large prostates, simple prostatectomy can use an open, laparoscopic or robot-assisted approach. The choice relative to endoscopic enucleation depends on anatomy, available expertise and individual circumstances.

Minimally Invasive Surgical Therapies (MIST)

For men wishing to preserve sexual function (particularly ejaculation):

• UroLift (Prostatic Urethral Lift) — tiny implants deployed transurethral to retract obstructing lateral lobes; no tissue removal; designed to preserve ejaculation in selected patients. The implants remain in place; suitability depends on prostate anatomy and the specific device indication
• Rezūm (Water Vapour Thermal Therapy) — convective water vapour injected into the prostate; induces localised cell death; reduces prostate volume; the anaesthetic and treatment setting vary. Preservation of ejaculation is a treatment goal, not a guarantee
• Aquablation (AQUABEAM robotic system): robotic high-velocity waterjet ablation guided by real-time ultrasound imaging; may preserve ejaculation better than TURP in selected patients; suitability depends on prostate size, anatomy and the treating team

BPH and Prostate Care in China

Ask the receiving urology service which assessments and treatments are appropriate and currently available. Depending on the findings, assessment may include IPSS scoring, urine tests, uroflowmetry, residual-volume ultrasound and selected further investigations.

If a procedure is proposed, confirm the exact technique, surgeon, admission plan, risks to ejaculation and fertility, catheter care and follow-up. Availability of HoLEP, TURP, UroLift or Rezūm must be confirmed with that institution; this article does not establish availability or same-admission treatment.

Obtain an itemised hospital quotation and confirm language support and any PriumCare coordination separately before making travel plans.

Contact a PriumCare care navigator to arrange a BPH assessment, uroflowmetry, or prostate surgery consultation.

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Sources and editorial correction

• NIDDK: enlarged prostate.

• NICE: male lower urinary tract symptoms.

• NHS: ejaculation problems.

• EAU: male LUTS management.

• PLESS trial, 1998.

• US tadalafil prescribing information.

• NICE: UroLift permanent implants.

• Rezūm outpatient feasibility study, 2024.

• NICE: Aquablation evidence.

• Additional targeted source.

• Additional targeted source.

• Additional targeted source.

Second-pass editorial clarification: 25 October 2026. Additional checks addressed the specific definitions, treatment eligibility and risk-classification statements documented here. This does not constitute a whole-article medical review.

Editorial source correction: 25 October 2026. Targeted checks addressed medication advice, ejaculatory effects, symptom-score interpretation, named procedures and unsupported availability comparisons. This is not a clinical review of the whole article. No named medical reviewer is claimed. Original publication date is retained.

Additional targeted source clarification

Editorial source check: 25 October 2026. These changes clarify selected test indications, medicine selection and evidence limits. They are not a whole-article medical review. Original publication date is retained.

• EAU: diagnostic evaluation and selective urodynamics
• EAU: antimuscarinics, residual urine and beta-3 agonists
• MHRA: mirabegron and severe uncontrolled hypertension