What tests are used to diagnose Benign Prostatic Hyperplasia (BPH)?

Diagnostic Tests for Benign Prostatic Hyperplasia

The diagnosis of BPH requires a mandatory initial evaluation consisting of medical history, AUA Symptom Index (IPSS), digital rectal examination, urinalysis, and selective PSA testing in men with ≥10 years life expectancy, with additional optional tests reserved only for specific clinical scenarios or when invasive therapy is planned. 1, 2

Mandatory Initial Tests

The following tests must be performed in all patients being evaluated for BPH:

Medical History and Symptom Assessment

• Document the onset, duration, and severity of lower urinary tract symptoms, including both obstructive symptoms (weak stream, hesitancy, incomplete emptying) and irritative symptoms (frequency, urgency, nocturia) 1, 3
• Administer the AUA Symptom Index (identical to the seven symptom questions of the IPSS) at the initial visit to quantify symptom severity: mild (0-7), moderate (8-19), or severe (20-35) 1, 2
• Include the Disease Specific Quality of Life question to measure how bothered the patient is by symptoms, as this determines whether intervention is appropriate more than symptom severity alone 2
• Review all current medications to exclude drug-induced voiding dysfunction as an alternative cause of symptoms 1
• Assess risk factors including family history of prostate disease and fitness for potential surgical procedures 1

Physical Examination

• Perform digital rectal examination (DRE) to assess prostate size and consistency, and to exclude locally advanced prostate cancer 1, 4, 3
• Conduct focused neurologic examination assessing mental status, ambulatory status, lower extremity neuromuscular function, and anal sphincter tone 1

Laboratory Testing

• Perform urinalysis via dipstick testing or microscopic examination of urine sediment to screen for hematuria and urinary tract infection 1, 3
• Offer PSA testing to men with at least 10 years life expectancy for whom knowledge of prostate cancer would change management 1, 2

Important caveat: Serum creatinine is NOT routinely indicated in initial evaluation, as baseline renal insufficiency is no more common in men with BPH than in the general population 2

Optional Tests (Selective Use Only)

These tests are NOT necessary prior to watchful waiting or medical therapy, but may be considered in specific circumstances:

Uroflowmetry and Post-Void Residual (PVR)

• Consider when initial evaluation suggests non-prostatic cause of symptoms, patient selects invasive therapy, or results would change management 2
• Men with maximum flow rate (Qmax) <10 mL/sec are more likely to have urodynamic obstruction and benefit from surgery 1, 2
• Large PVR volumes (e.g., 350 mL) may indicate bladder dysfunction and potentially herald disease progression, but elevated PVR is NOT a contraindication to conservative or medical management 2

Pressure-Flow Urodynamic Studies

• Only indicated when invasive therapies are being considered, particularly for men with flow rates >10 mL/sec when surgery is contemplated 5, 1, 2
• Consider in men with concomitant neurologic disease (stroke, Parkinson's disease, neuropathy) or history of prior invasive therapy for BPH 5
• The 5th International Consultation on BPH recommends uroflowmetry for all men who choose invasive or minimally invasive therapy, followed by pressure-flow studies in those with Qmax >10 mL/sec 5

Urethrocystoscopy

• Appropriate in men with history of microscopic or gross hematuria, urethral stricture (or risk factors such as history of urethritis or urethral injury), bladder cancer, or prior lower urinary tract surgery (especially TURP) 5, 6, 1
• Should NOT be used in initial evaluation of patients without these risk factors or solely to determine "need for treatment" 5, 6
• NOT routinely necessary prior to watchful waiting or medical therapy 5, 6
• The endoscopic appearance of the prostatic urethra and bladder does NOT predict response to BPH therapy, though it may guide choice of therapy in patients who have already decided to proceed with invasive treatment 5, 6

Prostate Ultrasound (Transrectal or Transabdominal)

• May be appropriate when minimally invasive or surgical interventions are chosen, as prostate size and shape are important for selecting patients for specific therapies 5, 6, 1
• NOT routinely necessary prior to watchful waiting or medical therapy 5, 6
• Helps guide selection between TUIP versus TURP and assesses anatomical features such as intravesical lobes 6

Urine Cytology

• Consider in men with predominantly irritative symptoms, especially those with smoking history or other risk factors for bladder cancer 2

Tests NOT Recommended

• Filling cystometrography (CMG) is not recommended for typical BPH patients 1
• Upper urinary tract imaging (ultrasound or excretory urography) is not recommended unless hematuria, UTI, renal insufficiency, or history of urolithiasis or urinary tract surgery is present 1, 2

Common Pitfalls to Avoid

• Do not perform cystoscopy as part of routine initial BPH evaluation, as it adds unnecessary cost and invasiveness without improving outcomes in patients without specific risk factors 6
• Do not use symptom scores alone to determine need for intervention—it is critical to assess how bothersome symptoms are to the individual patient 2
• Do not order uroflowmetry before starting alpha-blockers, as symptom response to alpha-blockers is not dependent on baseline flow rate 2
• Do not withhold treatment based solely on elevated PVR, as it is not a contraindication to conservative or medical management 2
• Do not use cystoscopic findings to predict treatment response—anatomy may guide therapy selection, but appearance itself does not predict outcomes 6

Follow-Up Testing

• Readminister IPSS at each follow-up visit to objectively assess symptom changes 1
• Annual follow-up is recommended for patients with mild symptoms who choose watchful waiting 2