Acute infection of the renal pelvis or parenchyma
Acute pyelonephritis is usually due to ascending infection; in uncomplicated cases the offending organism is usuallyEscherichia coli(75%)
Severe variants of pyelonephritis are seen where complicating factors or stasis, stones, impaired immunity, structural defect, or diabetes exist; these are also known as complicated pyelonephritis
Synonyms