What is the next step in evaluating a patient with hematuria (blood in urine) and no diagnosed Urinary Tract Infection (UTI)?

Evaluation of Hematuria with No UTI

For patients with hematuria (blood in urine) and no diagnosed UTI, a complete urologic evaluation is recommended, including cystoscopy and imaging, with CT urography being the preferred imaging modality. 1

Risk Stratification Approach

The American Urological Association (AUA) and the Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction (SUFU) recommend classifying patients with microhematuria into risk categories:

Risk Level	Criteria
Low (0-0.4%)	3-10 RBC/HPF + Age <60 years (women) or <40 years (men) + Non-smoker or <10 pack-years
Intermediate (0.2-3.1%)	11-25 RBC/HPF or Age 60+ (women)/40-59 (men) or 10-30 pack-years smoking
High (1.3-6.3%)	>25 RBC/HPF or Age 60+ (men) or >30 pack-years smoking [1]

Initial Diagnostic Steps

1. Confirm hematuria microscopically

   • Dipstick positivity alone is not reliable and requires microscopic confirmation showing ≥3 erythrocytes per high-powered field 2, 1
   • This applies even if the patient is on antiplatelet or anticoagulant therapy 2

2. Laboratory evaluation

   • Complete blood count
   • Serum creatinine and BUN
   • Urinalysis with microscopic examination of urinary sediment
   • 24-hour urine collection to quantify protein excretion 1

3. Assess for glomerular vs. non-glomerular hematuria

   • Presence of red cell casts, dysmorphic RBCs, or significant proteinuria (>1,000 mg/24 hours) suggests glomerular disease requiring nephrology referral 1

Imaging and Diagnostic Procedures

For Non-Glomerular Hematuria:

1. CT Urography (preferred imaging modality - 92% sensitivity, 93% specificity) 1

2. Alternative imaging options:

   • MR Urography: For patients with contrast allergy or renal insufficiency
   • Renal Ultrasound: Alternative or for younger patients (50% sensitivity, 95% specificity) 1

3. Cystoscopy

   • Recommended for all patients ≥35 years with microscopic hematuria
   • Particularly important in high-risk patients 1

4. Avoid unnecessary tests:

   • Urinary cytology or other urine-based molecular markers are not recommended for initial evaluation 2

Special Considerations

• Gross hematuria: Requires immediate urologic referral even if self-limited 2
• Anticoagulant/antiplatelet therapy: Not to be assumed as the cause of hematuria; evaluation should still proceed 2, 1
• UTI presence: Does not exclude the possibility of urologic malignancy; one study found 20% of patients with positive urine cultures had urologic malignancy 3

Follow-Up for Negative Initial Evaluations

For patients with persistent asymptomatic microscopic hematuria after negative initial evaluations:

• Low-risk patients: Annual urinalysis
• Intermediate/high-risk patients: Consider urine cytology and repeat urinalysis at 6,12,24, and 36 months 1
• Immediate re-evaluation if recurrent gross hematuria, abnormal urinary cytology, or new irritative voiding symptoms occur 1

Common Pitfalls to Avoid

1. Assuming UTI as the cause without proper evaluation: Even with a positive urine culture, urologic malignancy may be present 3

2. Neglecting nephrology evaluation when there are signs of glomerular disease 1

3. Attributing hematuria to anticoagulant/antiplatelet therapy without complete evaluation 2, 1

4. Using screening urinalysis for cancer detection in asymptomatic adults 2

5. Relying solely on dipstick testing without microscopic confirmation 2