Question: why is pyelonephritis more common on the right?
Answer: Urinary stasis can serve as a reservoir for bacteria. Urinary stasis and the presence of vesicoureteral reflux predispose some women to acute pyelonephritis. Calyceal and ureteral dilatation are more common on the right side; in up to 80% of cases, the dilatation is localized to the right.