Nephritis

Nephritis is inflammation of the kidneys. It may involve the glomeruli, tubules, or interstitial tissue surrounding the glomeruli and tubules.
Nephritis is often caused by infections, and toxins, but is most commonly caused by autoimmune disorders that affect the major organs like kidneys.
Nephritis can produce glomerular injury, by disturbing the glomerular structure with inflammatory cell proliferation. This can lead to reduced glomerular blood flow, leading to reduced urine output (oliguria) and retention of waste products (uremia). As a result, red blood cells may leak out of damaged glomeruli, causing blood to appear in the urine (hematuria).