hi thank your for the query sir/madam , after going through your query I would like to suggest you to see your urologist and get an appointment for surgery....sir renal stones of size 6 mm are an indication for surgery in your case size of the calculi is 8 mm and along with complication of swelling of the kidney which in my opinion could be an hydrouretero nephrosis..this would worsen your renal function if delayed further..get a CT abdomen done to check for any stones lower down in ureter.. hope I have answered your query wish you good health thank you regards DR Alekhya