What are the hallmark signs of nephrotic syndrome?

The hallmark signs of nephrotic syndrome include proteinuria, edema, hypoalbuminemia, and hyperlipidemia.

Proteinuria occurs due to increased permeability of the glomerular membrane, allowing proteins to escape into the urine, which is a primary characteristic of nephrotic syndrome. Edema results because the loss of protein, particularly albumin, leads to a decrease in oncotic pressure within the blood vessels, causing fluid to leak into the interstitial spaces. Hypoalbuminemia directly relates to the significant loss of albumin in urine, contributing to the edema and other associated symptoms. Hyperlipidemia is also prevalent in nephrotic syndrome due to alterations in lipid metabolism as a compensatory response to low serum albumin levels.

These components clearly define nephrotic syndrome and explain the clinical picture of affected individuals.