Which finding is most indicative of nephrotic syndrome?

• A. Heavy proteinuria
• B. Hematuria with RBC casts
• C. Hypertension in all cases
• D. Low lipid levels

Answer: (A)

Heavy proteinuria is the best clue because nephrotic syndrome is defined by the loss of large amounts of protein in the urine (typically more than 3.5 g/day). This proteinuira lowers blood albumin, reducing oncotic pressure and producing edema, while the liver responds by making more lipids, leading to hyperlipidemia. The other findings point to different kidney problems: blood in the urine with RBC casts indicates nephritic processes with glomerular inflammation; hypertension can occur in various kidney disorders and isn’t universal in nephrotic syndrome; and lipid levels are usually high, not low, in nephrotic syndrome. So heavy protein loss most clearly signals nephrotic syndrome.