What initial diagnostic tests, such as Complete Blood Count (CBC) and Urinalysis (UA), should be ordered for a patient presenting with hematuria?

Initial Diagnostic Testing for Hematuria

Yes, you should absolutely order both a CBC and urinalysis (UA) for a patient presenting with blood in the urine, with the UA being the essential first test and the CBC providing important supplementary information. 1

Essential First Step: Urinalysis with Microscopy

• Order a urinalysis with microscopic examination immediately - this is the cornerstone diagnostic test for any patient reporting blood in urine 1, 2
• The microscopic examination must confirm ≥3 red blood cells per high-power field (RBC/HPF) to establish true hematuria, as dipstick testing alone is insufficient and prone to false positives 1, 2
• Ensure proper specimen collection using a clean-catch, midstream technique to avoid contamination 1
• The urinalysis should assess for:
  • Number and morphology of RBCs (dysmorphic vs. normal-shaped) 1
  • Presence of red cell casts (indicates glomerular disease) 1
  • White blood cells and bacteria (to rule out infection) 3
  • Proteinuria (significant if >500 mg/24 hours) 1

Complete Blood Count (CBC)

• A CBC is appropriate and recommended as part of the initial laboratory evaluation 3
• The CBC helps assess for:
  • Anemia (which may indicate chronic or significant blood loss)
  • Infection markers if UTI is suspected
  • Baseline hematologic status

Additional Essential Labs

• Serum creatinine to assess renal function 3, 1
• Urine culture if urinalysis suggests infection (presence of WBCs, bacteria, positive leukocyte esterase or nitrites) 1

Critical Next Steps Based on Initial Results

If Infection is Present:

• Treat the UTI appropriately and repeat urinalysis 6 weeks after treatment to confirm resolution of hematuria 3, 1
• If hematuria persists after infection treatment, proceed with full urologic evaluation 1

If Glomerular Source is Suspected:

• Indicators include: dysmorphic RBCs (>80%), red cell casts, significant proteinuria (>500 mg/24 hours), or elevated creatinine 1, 4
• Refer to nephrology for further evaluation 1, 4

If Non-Glomerular (Urologic) Source:

• Indicators include: normal-shaped RBCs, minimal/no proteinuria, normal creatinine 4
• Refer to urology for cystoscopy and imaging (CT urography preferred) 1, 4

Gross vs. Microscopic Hematuria

• If the patient reports visible blood (gross hematuria), this requires urgent urologic referral regardless of other findings due to high malignancy risk (30-40%) 4
• Do not delay referral even if the bleeding has stopped 4
• Never attribute hematuria solely to antiplatelet or anticoagulant medications without complete evaluation 1, 4

Common Pitfalls to Avoid

• Do not rely on dipstick results alone - always confirm with microscopic examination, as dipstick can give false positives from myoglobinuria, hemoglobinuria, or contamination 2
• Do not skip urologic evaluation in women - women are often under-evaluated despite having higher bladder cancer mortality rates 2
• Do not assume benign cause without confirmation - even in patients on anticoagulation, hematuria warrants full investigation 4