What are the recommended steps if I have hematuria (blood in the urine)?

Blood in Urine: Evaluation and Management

Immediate Action Required

If you have visible blood in your urine (gross hematuria), you need urgent urologic referral for cystoscopy and imaging, even if the bleeding stops on its own, because the risk of underlying cancer exceeds 10%. 1, 2

First Step: Confirm True Hematuria

• Do not rely on dipstick alone - a positive dipstick test must be confirmed with microscopic examination showing ≥3 red blood cells per high-power field, as dipstick specificity is only 65-99% 3, 1
• Collect a clean-catch midstream urine specimen for microscopic analysis 3
• Rule out false positives from menstruation, vigorous exercise within 48 hours, or recent sexual activity 1

Distinguish Between Gross and Microscopic Hematuria

Gross (Visible) Hematuria

• Requires immediate urologic referral regardless of whether bleeding is ongoing or has resolved 1, 2
• Cancer risk is 30-40% in these patients 1, 2
• Painless gross hematuria has stronger association with malignancy than hematuria with flank pain 4, 2

Microscopic Hematuria

• Defined as ≥3 red blood cells per high-power field on microscopic examination 3, 1
• Should be confirmed on two of three properly collected specimens before proceeding with extensive workup 3, 1
• Cancer risk is 2.6-4%, significantly lower than gross hematuria 1, 2

Critical Rule: Anticoagulation Is Not an Excuse

Do not attribute hematuria to blood thinners (warfarin, aspirin, clopidogrel, etc.) - these medications may unmask underlying pathology but do not cause hematuria themselves. Full evaluation is still required. 1, 4, 2

Determine the Source: Glomerular vs. Non-Glomerular

Signs of Glomerular (Kidney) Disease - Needs Nephrology

• Significant proteinuria (protein-to-creatinine ratio >0.2) 1
• Dysmorphic red blood cells (>80% abnormal-shaped RBCs) 1
• Red cell casts in urine (pathognomonic for glomerular disease) 1
• Tea-colored urine 1
• Elevated serum creatinine or declining kidney function 1

Signs of Non-Glomerular (Urologic) Disease - Needs Urology

• Normal-shaped red blood cells (>80%) 1
• Minimal or no proteinuria 2
• Normal kidney function 2
• History of smoking, age >35-40 years, or occupational chemical exposure 1

Required Workup for Confirmed Hematuria

Laboratory Tests

• Urine culture to rule out infection (must be done before antibiotics if infection suspected) 1, 2
• Serum creatinine and BUN to assess kidney function 1, 2
• Complete urinalysis with microscopic examination for RBC morphology, casts, and protein 2
• Do NOT obtain urine cytology in initial evaluation - it is not recommended by current guidelines 4

Imaging

• CT urography (multiphasic CT with IV contrast) is the preferred imaging modality for comprehensive upper urinary tract evaluation 1, 2
• MR urography if CT is contraindicated 2
• Renal ultrasound is inferior but acceptable if CT/MR unavailable 2

Cystoscopy

• Required for all patients with gross hematuria 1, 2
• Required for microscopic hematuria without identified benign cause 1
• Performed by urologist to visualize bladder and urethra directly 2

Risk Stratification for Microscopic Hematuria

High-Risk Patients (Require Full Urologic Evaluation After Single Positive Test)

• Age: Men ≥60 years, Women ≥60 years 1
• Smoking history >30 pack-years 1
• Occupational exposure to chemicals or dyes 3, 1
• History of prior gross hematuria 3
• History of urologic disorders or pelvic radiation 3

Intermediate-Risk Patients

• Age: Men 40-59 years, Women with any smoking history 1
• Smoking 10-30 pack-years 1
• Degree of hematuria: 11-25 RBCs per high-power field 1

Lower-Risk Patients (Still Require Evaluation if Persistent)

• Age: Men <40 years, Women <60 years who never smoked 1
• Smoking <10 pack-years 1
• Degree of hematuria: 3-10 RBCs per high-power field 1

When to Refer to Nephrology Instead of Urology

• Presence of significant proteinuria with hematuria 1
• Red cell casts or >80% dysmorphic RBCs 1
• Elevated creatinine or declining kidney function 1
• Development of hypertension with persistent hematuria 1, 2

Follow-Up Protocol if Initial Workup is Negative

• Repeat urinalysis at 6,12,24, and 36 months 1, 2
• Monitor blood pressure at each visit 1, 2
• Consider nephrology referral if hematuria persists with new hypertension, proteinuria, or glomerular bleeding features 1, 2
• Immediate urologic reevaluation if any of the following develop: recurrent gross hematuria, abnormal cytology, or irritative voiding symptoms without infection 2

Common Pitfalls to Avoid

• Never ignore gross hematuria, even if self-limited - cancer risk is too high 1, 2
• Do not defer evaluation in patients on anticoagulation - these medications unmask rather than cause bleeding 1, 4
• Do not skip confirmation with microscopy - dipstick alone has poor specificity 3, 1
• Do not assume urinary tract infection explains hematuria - treat the infection but reevaluate with repeat urinalysis after treatment to ensure resolution 1
• Do not delay urologic referral while waiting for other test results in patients with gross hematuria 2