How glomerulonephritis cause renal failure?

Glomerulonephritis can cause renal failure through several mechanisms:

1. Direct Damage to Glomeruli: Glomerulonephritis primarily affects the glomeruli, the filtering units of the kidneys. Inflammation and damage to the glomeruli can impair their ability to filter waste products and fluids effectively, leading to a buildup of toxins and fluid retention.

2. Scarring and Obliteration of Glomeruli: Chronic glomerulonephritis can result in scarring and progressive destruction of the glomeruli, leading to their obliteration. This loss of functional glomerular units further reduces the kidney's filtration capacity and contributes to renal failure.

3. Reduced Blood Flow to Nephrons: Glomerulonephritis can cause inflammation and narrowing of the small blood vessels (afferent arterioles) that supply blood to the nephrons, the functional units of the kidneys. This decreased blood flow compromises the oxygen and nutrient supply to the nephrons, impairing their function and contributing to renal failure.

4. Tubulointerstitial Damage: Severe or prolonged glomerulonephritis can extend beyond the glomeruli and affect the adjacent tubules and interstitial tissue of the kidneys. This damage can further disrupt the filtration and reabsorption processes, leading to tubular dysfunction and contributing to renal failure.

5. Activation of Intrarenal Pathways: Glomerulonephritis can trigger the activation of various intrarenal pathways, such as the renin-angiotensin-aldosterone system and the complement system. These pathways, when overactivated, can perpetuate inflammation, fibrosis, and further damage to the kidneys, ultimately contributing to renal failure.

6. Systemic Effects: In some cases, severe glomerulonephritis can lead to systemic complications that indirectly contribute to renal failure. For example, uncontrolled hypertension associated with glomerulonephritis can strain the kidneys and accelerate their deterioration.

Overall, glomerulonephritis disrupts the delicate balance of fluid, electrolyte, and waste product homeostasis within the kidneys, leading to a decline in renal function and potentially culminating in renal failure if left untreated or inadequately managed.