Concepts
Non-clinical sciences/Lab medicine · Renal interpretation

Nephrotic vs nephritic syndrome

What it means

Nephrotic: proteinuria >3.5 g/24h (ACR high, PCR >300), hypoalbuminaemia, oedema, hyperlipidaemia — a leaky filtration barrier with BLAND urine (no casts). Causes: minimal change (children), membranous, FSGS, diabetic nephropathy, amyloid. Risk: VTE (antithrombin loss). Nephritic: haematuria with RED-CELL CASTS, hypertension, oliguria, mild-moderate proteinuria, AKI — inflammatory glomerulonephritis. Causes: post-streptococcal, IgA nephropathy, anti-GBM (Goodpasture), ANCA vasculitis, lupus.

Worked example

Frothy urine, protein 4+, albumin 21, gross oedema, normal BP, no casts → nephrotic. RBC casts + hypertension + oliguria + AKI → nephritic.

In the exam

A patient has heavy proteinuria (PCR 1100), hypoalbuminaemia and gross oedema but a normal blood pressure and no casts in the urine.

What settles it

Nephrotic = heavy protein + low albumin + oedema, BLAND urine; nephritic = haematuria + RED-CELL CASTS + hypertension + AKI (inflammatory).

Classically confused with

AKI — pre-renal, renal or post-renal

Source: NICE CKS; StatPearls