What could be causing my low urine output of 200-300ml per void?

Low Voided Volume Assessment

Voiding 200-300ml per episode is actually within normal range and does not indicate pathology by itself—normal voided volumes range from 200-500ml, with functional bladder capacity typically 300-600ml. 1

Understanding Your Voiding Pattern

Your concern likely stems from either:

• Increased urinary frequency (voiding more often than every 2-3 hours during the day, or more than once at night) 1
• Sensation of incomplete emptying despite voiding this volume 1
• Comparison to previous larger voided volumes 1

The key question is not the volume per void, but rather your total 24-hour urine output and voiding frequency pattern. 1

When This Volume Pattern Becomes Clinically Significant

If You're Voiding Frequently (>8 times/day or >1 time/night):

Storage symptoms (frequency, urgency, nocturia) are typically more bothersome than voiding symptoms and warrant evaluation. 2

• Complete a 3-day frequency-volume chart documenting each void time and volume to calculate total 24-hour output and identify patterns like nocturnal polyuria (>33% of daily urine produced at night) 1, 3
• Urinalysis is essential to exclude urinary tract infection, hematuria, or glycosuria 1
• Post-void residual ultrasound should be measured to determine if you're retaining urine after voiding 4, 5

If You Have Associated Symptoms:

Weak stream, straining, or incomplete emptying suggests bladder outlet obstruction requiring different evaluation than isolated frequency. 1

• In men with weak stream and dysuria, urethral stricture must be considered regardless of age, particularly if there's history of catheterization, instrumentation, or trauma 5
• Uroflowmetry showing peak flow <12 mL/second suggests significant obstruction from stricture or other causes 5
• Retrograde urethrography or urethrocystoscopy is recommended to confirm stricture diagnosis and characterize location/severity 4, 5

If You're an Older Man with Gradual Onset:

Alpha-blocker therapy (tamsulosin, alfuzosin) is first-line for lower urinary tract symptoms due to bladder outlet obstruction, with assessment at 2-4 weeks. 1, 2

• Combination therapy with 5-alpha reductase inhibitor should be added if prostate is enlarged or PSA >1.5 ng/ml, though benefit requires 3+ months 1
• Antimuscarinic agents can be safely combined with alpha-blockers when overactive bladder symptoms (urgency, frequency) coexist with obstruction 1

Critical Red Flags Requiring Urgent Evaluation

• Dipstick hematuria mandates imaging and endoscopy of the urinary tract 1
• Rapidly decreasing GFR or rapidly increasing proteinuria suggests alternative kidney pathology 1
• Refractory hypertension with urinary symptoms warrants investigation for secondary causes 1
• Active urinary sediment or signs of systemic disease require comprehensive evaluation 1

Common Pitfalls to Avoid

• Do not rely on single measurements—post-void residual and uroflowmetry have marked intra-individual variability and require repeat testing 4
• Do not assume benign prostatic enlargement is the sole cause in middle-aged men with voiding symptoms; urethral stricture is frequently missed 5
• Do not treat empirically without urinalysis when dysuria is present, as multiple infectious and non-infectious causes exist 6, 7
• Failing to obtain frequency-volume chart when nocturia is bothersome prevents identification of nocturnal polyuria, which requires different management than bladder pathology 1

Practical Next Steps

Start with a 3-day frequency-volume chart and urinalysis—these simple tests will determine whether your voiding pattern represents normal variation or requires further urological evaluation. 1, 4

If total 24-hour urine output is normal (1500-2000ml) and you're simply voiding smaller volumes more frequently, focus shifts to identifying storage symptoms versus obstruction. 1 If post-void residual is elevated (>100-150ml), obstruction evaluation with flow studies and imaging becomes necessary. 4, 5