Nephrotic Syndrome
Overview
Plain-Language Overview
Nephrotic Syndrome is a condition that affects the kidneys, which are vital organs responsible for filtering waste and excess fluids from the blood. In this syndrome, the kidneys leak large amounts of protein into the urine, which is not normal. This protein loss leads to low levels of protein in the blood, causing fluid to build up in tissues and resulting in swelling or edema, especially in the legs and around the eyes. People with this condition may also experience fatigue and an increased risk of infections and blood clots. The syndrome primarily impacts the body's ability to maintain proper fluid balance and protect against infections.
Clinical Definition
Nephrotic Syndrome is defined by a group of clinical findings resulting from increased permeability of the glomerular filtration barrier, leading to massive proteinuria (>3.5 g/day), hypoalbuminemia, and subsequent edema. The core pathology involves damage to the glomerular basement membrane or podocytes, often due to primary glomerular diseases such as minimal change disease, focal segmental glomerulosclerosis, or secondary causes like diabetes mellitus and systemic lupus erythematosus. The loss of plasma proteins, especially albumin, reduces plasma oncotic pressure, causing fluid to shift into the interstitial space. Additionally, patients are at risk for hyperlipidemia due to increased hepatic lipoprotein synthesis and hypercoagulability from urinary loss of anticoagulant factors. The syndrome is clinically significant because it predisposes to complications including infections, thromboembolism, and progressive kidney damage.