What is the next step for a healthy adult male presenting with abdominal and lower back pain, trace hematuria on urinalysis (urine analysis), who takes medication for headaches?

Immediate Next Step: Confirm True Hematuria with Microscopic Urinalysis

You must first confirm true microscopic hematuria by obtaining a microscopic urinalysis showing ≥3 red blood cells per high-power field (RBC/HPF) on at least two of three properly collected clean-catch midstream urine specimens before initiating any further workup. 1 A dipstick showing "trace lysed blood" has only 65-99% specificity and can produce false positives from myoglobin, hemoglobin, and other substances. 1, 2

Why Confirmation is Critical Before Proceeding

• Dipstick alone is insufficient for diagnosis—you need microscopic confirmation of ≥3 RBCs/HPF to establish true hematuria and justify the extensive evaluation that follows. 1, 3
• If microscopic examination shows 0-2 RBCs/HPF, this falls within the normal range and does not warrant urologic workup (no cystoscopy, no CT urography). 1
• The American Urological Association explicitly states that "a dipstick reading suggestive of hematuria should not lead to imaging or further investigation without confirmation of three or greater red blood cells per high power field." 1

If Microscopic Hematuria is Confirmed (≥3 RBCs/HPF)

Exclude Transient Benign Causes First

• Rule out urinary tract infection by obtaining urine culture if infection is suspected (dysuria, urgency, frequency). 1 If positive, treat appropriately and repeat urinalysis 6 weeks after treatment—if hematuria resolves, no additional evaluation is necessary. 1
• Exclude recent vigorous exercise, sexual activity, or viral illness as these can cause transient hematuria. 1, 3 Repeat urinalysis 48 hours after cessation of the activity—if hematuria resolves, no further evaluation is needed. 1

Risk Stratification for Malignancy

This patient's age and risk factors determine the urgency and extent of evaluation:

• Age: The patient's age places him in a specific risk category (males <40 years = low risk, 40-59 years = intermediate risk, ≥60 years = high risk). 1
• Smoking history: Never smoker or <10 pack-years = low risk; 10-30 pack-years = intermediate risk; >30 pack-years = high risk. 1
• Degree of hematuria: 3-10 RBC/HPF = low risk; 11-25 RBC/HPF = intermediate risk; >25 RBC/HPF = high risk. 1
• History of gross hematuria: Any history automatically elevates to high risk. 1
• Occupational exposure: Exposure to benzenes, aromatic amines, or other chemicals/dyes = high risk. 1, 3

Distinguish Glomerular from Non-Glomerular Sources

Examine the urinary sediment carefully to determine if nephrology referral is needed in addition to urologic evaluation:

• Glomerular indicators (suggest nephrology referral): Tea-colored or cola-colored urine, >80% dysmorphic RBCs, red blood cell casts (pathognomonic for glomerular disease), significant proteinuria (protein-to-creatinine ratio >0.2 g/g), or elevated serum creatinine. 1, 3
• Non-glomerular indicators (proceed with urologic evaluation): Bright red blood, <80% dysmorphic RBCs, absence of proteinuria or only trace amounts, normal renal function. 1

Complete Urologic Evaluation for Confirmed Non-Glomerular Hematuria

If microscopic hematuria is confirmed and no benign cause is identified, proceed with:

1. Upper tract imaging: Multiphasic CT urography is the preferred modality for detecting renal cell carcinoma, transitional cell carcinoma, and urolithiasis. 1, 3 This includes unenhanced, nephrographic phase, and excretory phase images. 1

2. Cystoscopy: Mandatory for intermediate- and high-risk patients to evaluate for bladder transitional cell carcinoma. 1 Flexible cystoscopy is preferred over rigid cystoscopy due to less pain and equivalent or superior diagnostic accuracy. 1, 3

3. Laboratory evaluation: Serum creatinine to assess renal function, complete metabolic panel, and complete blood count with platelets. 1

4. Voided urine cytology: Consider in high-risk patients (age >60, smoking history, occupational exposure) to detect high-grade urothelial carcinomas. 1

Critical Pitfalls to Avoid

• Never attribute hematuria to headache medications (even if NSAIDs or antiplatelet agents)—these medications may unmask underlying pathology but do not cause hematuria themselves, and evaluation must proceed regardless. 1, 3
• Do not defer evaluation based on the patient being "otherwise healthy"—microscopic hematuria carries a 0.5-5% overall cancer risk, but 7-20% in higher-risk subgroups. 1
• Do not rely on dipstick alone—confirm with microscopic urinalysis showing ≥3 RBCs/HPF before initiating extensive workup. 1, 2

Follow-Up Protocol if Initial Evaluation is Negative

If complete workup is negative but hematuria persists:

• Repeat urinalysis at 6,12,24, and 36 months with blood pressure monitoring at each visit. 1, 4
• Immediate re-evaluation is warranted if: Gross hematuria develops, significant increase in microscopic hematuria occurs, new urologic symptoms appear (irritative voiding, flank pain, dysuria), or development of hypertension/proteinuria. 1
• After two consecutive negative annual urinalyses, no further testing for asymptomatic microhematuria is necessary. 1