What are the core diagnostic criteria for nephrotic syndrome?

• A. Proteinuria >3.5 g/day, hypoalbuminemia, edema, and hyperlipidemia.
• B. Proteinuria >1 g/day, edema, hyponatremia, hyperlipidemia.
• C. Hematuria, edema, high creatinine, hypolipidemia.
• D. Proteinuria >3.5 g/day, hypertension, edema, hypocalcemia.

Answer: (A)

Nephrotic syndrome is diagnosed by a quartet of findings that reflect substantial protein loss and its consequences: heavy proteinuria, low serum albumin (hypoalbuminemia), edema, and hyperlipidemia. Proteinuria exceeding about 3.5 g per day shows the kidneys are leaking large amounts of protein. This loss of albumin lowers the blood’s oncotic pressure, causing fluid to shift into tissues and produce edema. In response to hypoalbuminemia, the liver increases production of lipoproteins, leading to hyperlipidemia. Together, these features define nephrotic syndrome and explain why this option fits best.

The other choices don’t fit because they either cite an insufficient level of proteinuria, include hyponatremia which isn’t part of the nephrotic criteria, or present findings more typical of nephritic processes (like hematuria and higher creatinine) or non-defining features (such as hypertension or hypocalcemia).