Nephritic Syndrome

Nephritic syndrome is a condition that affects the kidneys, which are vital organs responsible for filtering waste and excess fluids from the blood. It causes inflammation in the tiny blood vessels of the kidneys, leading to damage that impairs their filtering ability. This results in symptoms such as blood in the urine (hematuria), swelling (edema), and high blood pressure. People with this condition may notice their urine looks dark or tea-colored due to the presence of red blood cells. The inflammation also reduces the kidneys' ability to remove waste, which can affect overall health. Protein loss in urine is usually less severe than in other kidney diseases but still contributes to symptoms. Early detection is important to prevent further kidney damage.

Nephritic syndrome is characterized by glomerular inflammation leading to impaired renal filtration and a clinical constellation of hematuria, azotemia, hypertension, and mild to moderate proteinuria. The underlying pathology involves immune-mediated injury to the glomerular capillary walls, often due to immune complex deposition or anti-glomerular basement membrane antibodies. This inflammation causes endothelial and mesangial cell proliferation, resulting in reduced glomerular filtration rate and leakage of red blood cells into the urine. Common causes include post-infectious glomerulonephritis, IgA nephropathy, and rapidly progressive glomerulonephritis. The syndrome is clinically significant because it can progress to acute kidney injury and chronic kidney disease if untreated. Histologically, it is distinguished by glomerular hypercellularity and crescent formation in severe cases.