Which complication is commonly associated with acute pyelonephritis?

Acute pyelonephritis primarily results from a bacterial infection of the kidneys, and one of its potential complications is renal abscess formation. The acute inflammation and infection can lead to the development of localized collections of pus within the renal parenchyma, resulting in abscesses. These collections can cause significant pain, fever, and further kidney damage if not addressed promptly.

Obstruction of the urinary tract is related to the urinary flow dynamics and can complicate pyelonephritis; however, it is not as direct a complication specifically associated with the infection as renal abscess formation.

While diabetes mellitus is a significant risk factor for urinary tract infections and can increase susceptibility to acute pyelonephritis, it is not a direct complication resulting from it. Chronic renal failure, although it can be a long-term outcome in cases of recurrent or untreated pyelonephritis, is not an immediate complication, as acute pyelonephritis typically requires timely treatment to prevent progression to chronic conditions.

Therefore, renal abscess formation reflects a direct consequence of the acute inflammatory process triggered by pyelonephritis, making it a commonly accompanying complication of this condition.