Edema in nephrotic syndrome is due to
**Core Concept**
Nephrotic syndrome is characterized by severe proteinuria, leading to hypoalbuminemia. The underlying mechanism of edema in this condition involves the loss of albumin, which plays a crucial role in maintaining **oncotic pressure**.
**Why the Correct Answer is Right**
The correct answer is related to the decrease in **oncotic pressure** due to hypoalbuminemia, causing fluid to shift from the vascular space to the interstitial space, resulting in edema. Normally, **albumin** helps retain fluid within the blood vessels.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because while **sodium retention** can contribute to edema, it is not the primary cause in nephrotic syndrome.
**Option B:** Incorrect as **lymphatic obstruction** is not directly related to the pathophysiology of nephrotic syndrome.
**Option C:** Incorrect because **capillary damage** is more relevant to other conditions, not nephrotic syndrome.
**Clinical Pearl / High-Yield Fact**
A key point to remember is that the edema in nephrotic syndrome is primarily due to the loss of **albumin**, making hypoalbuminemia a critical factor.
**Correct Answer:** D. Hypoalbuminemia due to loss of albumin in the urine.