Suggest Treatment For Kidney Infection

If someone has an assumed kidney infection made apparent by being swollen high up in the belly, like more towards the under carriage of the middle of the ribcage, WELL, CAN IT BE MADE WORSE IF A TABLESPOON OF REAL SUGAR WAS ADDED TO A 32 OZ. CUP OF 100% CRANBERRY JUICE? MY BOYFRIEND THINKS IM TRYING TO POISON HIM! JK LOL BUT WHAT OTHER REMEDIES MIGHT HELP CURE THE INFECTION AND HELP EASE HIS DISCOMFORT? PLZ HELP.... SINCERELY, L.COLBORN