KNOW Pyelonephritis is a bacterial infection of one or both kidneys.
Chronic cases are almost always secondary to some other disorder in the urinary tract.
Pregnancy, kidney stones, a bladder tumor, or a swollen prostate gland are among the leading culprits. Chronic pyelonephritis is always the result of a major underlying disorder, such as an unremedied obstruction, persistent large kidney stones, diabetes, or a constriction of the urinary tract. Some cases are caused by a continual backflow, or reflux, of urine from the bladder into the ureters, a problem that stems from failure of the ureters to close off while the bladder is emptying. In rare instances, bacteria reach the kidneys via the bloodstream rather than the urinary tract. You may also feel a constant need to urinate, even when your bladder is empty.