Hi,
Kidney problems are usually associated with edema or swelling in the legs. This occurs when the kidneys excrete an insufficient amount of sodium and fluid. The retained fluid increases pressure on the blood vessel walls. This allows fluids to move from inside the blood vessel to the space around the vessel, manifesting as swelling.
I hope this helps. Take care and do post us if you have more queries.
Just out of curiosity, are you having leg/joint pain while having a kidney infection as well? I am just doing research on my sisters behalf, BC she is just about to have a MRI for a "lump" on her kidney, but her legs have been aching as well.