Main cause of oedema in nephrotic syndrome is
**Core Concept**
Nephrotic syndrome is a clinical condition characterized by significant proteinuria, hypoalbuminemia, hyperlipidemia, and edema. The main cause of edema in nephrotic syndrome is related to the loss of albumin in the urine, leading to decreased oncotic pressure and fluid redistribution.
**Why the Correct Answer is Right**
The loss of albumin in nephrotic syndrome leads to a decrease in plasma oncotic pressure, causing fluid to shift from the intravascular space to the interstitial space. This results in edema. Albumin is a large protein that helps maintain blood volume by exerting oncotic pressure. When albumin is lost in the urine, the oncotic pressure decreases, allowing fluid to move out of the blood vessels and into the interstitial space, leading to edema.
**Why Each Wrong Option is Incorrect**
**Option A:** This option is not a relevant cause of edema in nephrotic syndrome. While fluid overload can cause edema, it is not the primary cause in nephrotic syndrome.
**Option B:** Hypoalbuminemia is a hallmark of nephrotic syndrome, but it is not the direct cause of edema. The loss of albumin leads to decreased oncotic pressure, which causes edema.
**Option C:** Hyperlipidemia is a common finding in nephrotic syndrome, but it is not the main cause of edema. The relationship between hyperlipidemia and edema is indirect, as hyperlipidemia is a consequence of the loss of albumin.
**Clinical Pearl / High-Yield Fact**
Remember the "6 Ps" of nephrotic syndrome: proteinuria, hypoalbuminemia, hyperlipidemia, edema, and often, a history of heavy proteinuria.
**Correct Answer:** B. Hypoalbuminemia.