Pyelonephritis is a serious bacterial infection of the kidney that can be acute or chronic.

One of the most common renal diseases, acute pyelonephritis is a sudden inflammation caused by bacteria. It primarily affects the interstitial area and the renal pelvis or, less often, the renal tubules.

Chronic pyelonephritis is persistent kidney inflammation that can scar the kidneys and may lead to chronic renal failure. This disease is most common in patients who are predisposed to recurrent acute...