Evaluation and Management of Hematuria (6-10 RBCs in Urine)
Definition and Initial Assessment
Microscopic hematuria is defined as ≥3 red blood cells per high-power field (HPF) on microscopic evaluation of urinary sediment from two of three properly collected urinalysis specimens, so a finding of 6-10 RBCs in urine requires a complete evaluation based on risk stratification. 1
The presence of 6-10 RBCs in urine falls within the definition of microscopic hematuria and specifically within the low-risk category according to current guidelines. However, this finding requires confirmation and proper evaluation:
- Dipstick positivity alone is insufficient and requires microscopic confirmation 1
- Confirmation should be done with microscopic urinalysis showing ≥3 RBC/HPF in 2 of 3 properly collected specimens 1
Risk Stratification
After confirming microscopic hematuria, risk stratification is essential to guide the evaluation:
| Risk Level | Criteria |
|---|---|
| Low/Negligible (0-0.4%) | 3-10 RBC/HPF + Age <60y (women) or <40y (men) + Never 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 |
Important risk factors to assess:
- Age (>60 years increases risk)
- Gender (male has higher risk)
- Smoking history (>30 pack-years is high risk)
- Exposure to industrial chemicals
- Family history of renal cancer
- History of pelvic radiation 1
Diagnostic Approach
1. Laboratory Evaluation
- Complete urinalysis with microscopic examination
- Assess for glomerular vs. non-glomerular source:
- Glomerular indicators: dysmorphic RBCs, RBC casts, significant proteinuria (>500-1000mg/24hr) 1
- Non-glomerular indicators: normal-shaped RBCs, absence of casts, minimal/no proteinuria
- Serum creatinine and BUN to assess renal function
- Complete blood count
- 24-hour urine collection to quantify protein excretion if glomerular disease is suspected 1
2. Imaging Studies Based on Risk Level
- Low-risk patients: Renal ultrasound (sensitivity 50%, specificity 95%) 1
- Intermediate-risk patients: Cystoscopy and renal ultrasound 1
- High-risk patients: Cystoscopy and CT urography (sensitivity 92%, specificity 93%) 1
- For patients with contrast allergy or renal insufficiency: MR urography as an alternative 1
- For pregnant patients: Ultrasound is the preferred initial imaging modality 1
3. Cystoscopy Recommendations
- All patients ≥35 years should undergo cystoscopy, regardless of risk level 1
- Mandatory for all patients with gross hematuria, regardless of resolution (sensitivity 87-100% for detecting bladder cancer) 1
Special Considerations
Distinguishing glomerular from non-glomerular hematuria:
Anticoagulation status:
Common pitfalls to avoid:
- Neglecting to evaluate leukocyturia without bacteriuria may miss non-infectious causes 1
- Assuming anticoagulation is the cause of hematuria without proper evaluation 1
- Failing to confirm dipstick-positive hematuria with microscopic examination 1
- Overlooking the possibility of urological disease in patients with dysmorphic RBCs 2
Follow-up and Surveillance
For patients with persistent hematuria after initial evaluation:
- Repeat urinalysis at 6,12,24, and 36 months 1
- Immediate re-evaluation if:
- Recurrent gross hematuria occurs
- Abnormal urinary cytology develops
- New irritative voiding symptoms appear 1
Treatment Approach
Treatment depends on the underlying cause identified during evaluation:
- Urinary tract infections: Appropriate antibiotics
- Urolithiasis: Medical expulsive therapy or surgical intervention
- Benign prostatic hyperplasia: Alpha-blockers or surgical intervention
- Glomerular disease: Referral to nephrology for possible renal biopsy and specific treatment 1
After treatment of a non-malignant cause, follow-up urinalysis should be performed to confirm resolution of hematuria 1.