Evaluation of Hematuria and Proteinuria

Initial Diagnostic Confirmation

The American College of Physicians recommends confirming true microscopic hematuria by documenting ≥3 red blood cells per high-power field on microscopic examination of at least two of three properly collected clean-catch midstream urine specimens, as dipstick positivity alone has only 65-99% specificity 2, 1
Quantify the proteinuria using a spot urine protein-to-creatinine ratio, with normal being <0.2 g/g, and note that the combination of proteinuria with hematuria significantly increases the likelihood of glomerular disease compared to hematuria alone 1

Examine the urinary sediment carefully for dysmorphic red blood cells, red blood cell casts, and urine color, as these features can suggest glomerular disease, with >80% dysmorphic RBCs strongly suggesting glomerular bleeding 1, 3
The presence of red blood cell casts is pathognomonic for glomerular disease 1

If glomerular origin is suspected, obtain a complete metabolic panel, complement levels, antinuclear antibody (ANA) and ANCA testing, and a complete blood count with platelets, to evaluate for post-infectious glomerulonephritis or lupus nephritis 1

Renal ultrasound is appropriate to evaluate kidney size, echogenicity, and structural abnormalities, with enlarged echogenic kidneys suggesting acute glomerulonephritis, and atrophic kidneys with altered corticomedullary differentiation indicating chronic glomerular disease 1, 3
CT urography and cystoscopy are not indicated in the initial evaluation of hematuria with proteinuria when glomerular disease is suspected, as these urologic evaluations are reserved for isolated hematuria without proteinuria or when non-glomerular bleeding is confirmed 3, 1

Immediate nephrology referral is indicated for persistent significant proteinuria, presence of red cell casts or >80% dysmorphic RBCs, elevated creatinine or declining renal function, or hypertension accompanying hematuria and proteinuria 1

Exclude menstrual contamination by ensuring urine collection is not during menses, and consider IgA nephropathy and post-infectious glomerulonephritis as common causes of combined hematuria and proteinuria in young adults 1, 3
Evaluate for systemic diseases, including lupus nephritis, which disproportionately affects young women and commonly presents with both hematuria and proteinuria 1