Nephrotic syndrome is characterized by significant edema, which often leads to hypervolemia. The underfill hypothesis suggests that proteinuria and hypoalbuminemia cause fluid leakage into the interstitial space, leading to intravascular hypovolemia and activation of neurohormonal compensatory mechanisms, such as the renin-angiotensin-aldosterone system (RAAS) and increased vasopressin, which further exacerbate edema. However, recent studies have revealed a kidney-limited sodium-reabsorption mechanism involving serine proteases that activate ENaC channels, leading to sodium reabsorption. Diuretic therapy remains crucial, but patients often exhibit diuretic resistance due to various factors, including high-sodium diets, poor compliance, and kidney dysfunction. Loop diuretics are the preferred initial choice, but combining diuretics may be effective in overcoming resistance. ENaC blockers are emerging as potential add-on treatments for nephrotic edema. The management of nephrotic edema is complex, and there is a need for more comprehensive guidelines and research to address fluid overload effectively.Nephrotic syndrome is characterized by significant edema, which often leads to hypervolemia. The underfill hypothesis suggests that proteinuria and hypoalbuminemia cause fluid leakage into the interstitial space, leading to intravascular hypovolemia and activation of neurohormonal compensatory mechanisms, such as the renin-angiotensin-aldosterone system (RAAS) and increased vasopressin, which further exacerbate edema. However, recent studies have revealed a kidney-limited sodium-reabsorption mechanism involving serine proteases that activate ENaC channels, leading to sodium reabsorption. Diuretic therapy remains crucial, but patients often exhibit diuretic resistance due to various factors, including high-sodium diets, poor compliance, and kidney dysfunction. Loop diuretics are the preferred initial choice, but combining diuretics may be effective in overcoming resistance. ENaC blockers are emerging as potential add-on treatments for nephrotic edema. The management of nephrotic edema is complex, and there is a need for more comprehensive guidelines and research to address fluid overload effectively.