Severe Proteinuria Causes and Clinical Correlations

Primary Glomerular Diseases

• Membranous nephropathy is a leading cause of nephrotic-range proteinuria in adults, with protein excretion often exceeding 4 g/day and requiring immunosuppressive therapy when persistent 1

Pregnancy-Related Causes

• Preeclampsia is a critical cause of severe proteinuria in pregnancy, with massive proteinuria (>5 g/24h) associated with significantly worse maternal and neonatal outcomes 2
• Proteinuria is not required for preeclampsia diagnosis, but when present at nephrotic levels, it indicates severe disease requiring close monitoring 2

Clinical Evaluation

• Do not delay quantification—when dipstick shows ≥2+ (approximately 1-3 g/L), confirm with spot protein/creatinine ratio or 24-hour collection, as values >1 g/L provide reasonable assessment of true severe proteinuria 2
• Remember that massive proteinuria (>5 g/24h) requires 24-hour urine collection for confirmation, particularly to assess need for thromboprophylaxis in nephrotic syndrome 2