Pyelonephritis may cause scars in kidney parenchyma and recurrent infections will increase the chance of chronic kidney disease (CKD) and eventually end-stage renal disease (ESRD) in long term. However, severe pyelonephritis may cause acute kidney failure. On the other hand, a complicated form of pyelonephritis that is called xanthogranulomatous pyelonephritis requires nephrectomy (surgical removal of affected kidney).