What is the evaluation and management of hematuria (blood in the urine)?

Evaluation and Management of Hematuria

All patients with gross hematuria should be referred for urologic evaluation, even if self-limited, while patients with microscopic hematuria should be risk-stratified to guide appropriate evaluation. 1, 2

Initial Assessment and Confirmation

• Confirm hematuria properly:

  • For dipstick-positive results, confirm with microscopic urinalysis showing ≥3 RBC/HPF before initiating further evaluation 1
  • Do not use screening urinalysis for cancer detection in asymptomatic adults 1

• Risk stratification is essential and should consider:

  • Age (>60 years is higher risk)
  • Smoking history
  • Exposure to industrial chemicals
  • Family history of renal cell carcinoma or genetic renal tumor syndromes
  • Degree of hematuria: <5 RBC/HPF (lower risk), ≥5 RBC/HPF (higher risk), gross hematuria (highest risk) 2

Diagnostic Approach

For Gross Hematuria

• Immediate urologic referral is mandatory regardless of other factors 1, 2
• Risk of malignancy exceeds 10% with gross hematuria 3

For Microscopic Hematuria

1. Initial laboratory evaluation:

   • Complete metabolic panel (BUN, creatinine, electrolytes)
   • Serum albumin and total protein
   • Urinalysis for pyuria, bacteriuria, crystals, and casts 2

2. Imaging:

   • CT urography is recommended for intermediate/high-risk patients (sensitivity 92%, specificity 93%) 2
   • MR urography for patients with renal insufficiency or contrast allergy
   • Renal ultrasound may be appropriate for lower-risk or younger patients 2

3. Cystoscopy:

   • Recommended for patients with risk factors for bladder cancer
   • Should be performed in conjunction with upper tract imaging in higher-risk patients 2

4. Additional testing based on clinical suspicion:

   • Urine cytology for patients with irritative voiding symptoms or risk factors for carcinoma in situ 2
   • Serum PSA for men with at least 10-year life expectancy 2

Important Clinical Considerations

• Anticoagulation is not an explanation for hematuria - patients on antiplatelet or anticoagulant therapy still require complete evaluation 1, 2

• Do not attribute hematuria to UTI without evidence of infection (pyuria, positive culture) 2

• Avoid common pitfalls:

  1. Assuming benign etiology without adequate workup
  2. Ignoring clinical changes (new symptoms, gross hematuria, increased microscopic hematuria)
  3. Failing to refer patients with gross hematuria (only 69-77% are currently referred) 4
  4. Inadequate evaluation of microscopic hematuria (only 36% are referred to urology) 5, 4

Follow-up and Surveillance

• After negative initial evaluation:

  • Repeat urinalysis within 12 months
  • If persistent microscopic hematuria, consider repeat evaluation 2

• Specialty referral indications:

  • Nephrology: Persistent significant proteinuria, elevated BUN/creatinine, eGFR <60 ml/min/1.73m² 2
  • Urology: Gross hematuria, abnormal genitourinary anatomy, suspected stones/tumors, persistent microscopic hematuria without proteinuria 2

Risk-Based Evaluation Algorithm

1. Gross hematuria: Immediate urology referral for cystoscopy and upper tract imaging
2. Microscopic hematuria with high-risk factors: Urology referral for cystoscopy and CT urography
3. Microscopic hematuria with low-risk factors: Consider less invasive imaging (ultrasound) initially, with follow-up urinalysis
4. Microscopic hematuria with signs of glomerular disease: Nephrology referral

Despite the prevalence of hematuria in primary care settings, studies show significant underutilization of appropriate evaluation pathways, particularly for microscopic hematuria 5, 4. This gap in care may lead to delayed diagnosis of serious conditions, including urologic malignancies.