**Core Concept**
Nephrotic syndrome is a clinical condition resulting from glomerular damage, leading to massive proteinuria, hypoalbuminemia, hyperlipidemia, and systemic fluid retention. It is defined by a constellation of signs and symptoms arising from impaired glomerular filtration and loss of plasma proteins into the urine.

**Why the Correct Answer is Right**
Nephrotic syndrome is characterised by **massive proteinuria** (>3.5 g/day), which causes **hypoalbuminemia** and triggers **hyperlipidemia** due to increased hepatic lipoprotein synthesis. The loss of oncotic pressure leads to **fluid leakage into tissues**, resulting in **edema**, particularly in the face, legs, and abdomen. All these features—proteinuria, hyperlipidemia, and edema—are integral to the diagnostic criteria and pathophysiology of the syndrome.

**Why Each Wrong Option is Incorrect**
Option A: While proteinuria is a hallmark, it is not sufficient alone to diagnose nephrotic syndrome; the condition requires **significant proteinuria** combined with other features. This option is incomplete.
Option B: Hyperlipidemia is a key feature due to compensatory hepatic response to low albumin, not a secondary effect. Omitting it makes the answer incomplete.
Option C: Edema is a direct consequence of hypoalbuminemia and fluid retention, so it is essential to the clinical picture. This option is also incomplete.

**Clinical Pearl / High-Yield Fact**
Remember the **"4 Ps"** of nephrotic syndrome: **P**roteinuria, **P**hospholipiduria, **H**yperlipidemia, and **E**dema. All must be present for diagnosis. Always check for hypoalbuminemia and signs of fluid overload.

✓ Correct Answer: D. All