Nephritic vs Nephrotic syndrome

Nephrotic and nephritic syndromes represent two contrasting clinical patterns of glomerular disease - the first dominated by protein loss and the second by inflammation and haematuria. Both arise from injury to the glomerulus, the kidney’s delicate filtration unit, but differ in their underlying pathophysiology, clinical features, and prognostic implications.

In nephrotic syndrome, the glomerular basement membrane becomes abnormally permeable, allowing large quantities of plasma proteins to leak into the urine. The resulting hypoalbuminaemia drives oedema, while hepatic lipoprotein synthesis leads to hyperlipidaemia. Common causes include minimal change disease in children and membranous nephropathy or diabetic nephropathy in adults.

By contrast, nephritic syndrome reflects an inflammatory process that disrupts the glomerular capillary wall. This inflammation leads to haematuria, hypertension, and a reduction in glomerular filtration rate (GFR). Classic causes include post-streptococcal glomerulonephritis, IgA nephropathy, and lupus nephritis.

💡 Teaching tip: Think of these as two ends of a spectrum - protein-leaky vs inflamed glomeruli. Many conditions (e.g. lupus nephritis, membranoproliferative GN) can present with mixed features, so clinical context and laboratory markers (urine microscopy, protein:creatinine ratio, complement levels) are key to differentiation.

In UK clinical practice, recognising the pattern quickly guides investigation and referral urgency. Patients with heavy proteinuria and oedema may require urgent diuretic therapy and specialist nephrology input, while those with nephritic features - especially with rapid renal function decline - often need same-day evaluation for rapidly progressive glomerulonephritis (RPGN).

Nephritic vs Nephrotic Syndrome 🧪🩺

Exam Pearl ✨: 👉 Nephritic = “Inflammatory, haematuria, hypertension” 👉 Nephrotic = “Proteinuria, hypoalbuminaemia, oedema, hyperlipidaemia”

🧑‍⚕️ Case Examples - Nephritic vs Nephrotic Syndromes

• Case 1 (Nephritic - Post-streptococcal GN): 🦠 A 10-year-old boy presents 2 weeks after a sore throat with dark cola-coloured urine, periorbital swelling, and hypertension. Urine dip shows haematuria and proteinuria, serum creatinine is raised. Diagnosis: Acute post-streptococcal glomerulonephritis (nephritic syndrome). Teaching point: Nephritic = haematuria + HTN + renal impairment, often post-infectious.
• Case 2 (Nephritic - Rapidly progressive GN): ⚡ A 34-year-old woman develops malaise, haematuria, and acute renal failure over 2 weeks. Urine shows red cell casts, ANCA is positive. Diagnosis: Rapidly progressive crescentic GN (vasculitis-associated nephritic syndrome). Teaching point: RPGN causes rapid loss of renal function and is a medical emergency requiring immunosuppression.
• Case 3 (Nephrotic - Minimal Change Disease): 🎈 A 6-year-old boy presents with generalized oedema (face, abdomen, legs). Urine dip shows 4+ protein, no blood. Serum albumin is 15 g/L, cholesterol elevated. Diagnosis: Minimal change disease (nephrotic syndrome). Teaching point: Nephrotic = heavy proteinuria, hypoalbuminaemia, oedema, hyperlipidaemia. Children often respond well to steroids.
• Case 4 (Nephrotic - Membranous Nephropathy): 🧪 A 55-year-old man presents with progressive ankle swelling and frothy urine. FBC normal, U&E shows preserved renal function. Urine protein 8 g/24h, renal biopsy shows thickened GBM with subepithelial deposits. Diagnosis: Membranous nephropathy (adult nephrotic syndrome). Teaching point: Common cause of nephrotic syndrome in adults, may be primary or secondary (e.g. malignancy, autoimmune, hepatitis).