Hello welcome to health care magic Thanks for your query. Yes hydroureteronephrosis causes damage to the kidney,,if the cause for this is not treated in time.. Normally kidneys produce the urine and flows from kidney, ureter,bladder and urethra.. If any obstruction in the outflow like calculus flow stops and the created back pressure exerts its effect on the kidney.. Due to this kidney enlarges in size and in due course of time kidney will go into failure.. You didn t mention in the query about the size of calculus Calculus of less than 5 mm size,,there is no medication required..drink more water so that it can dissolve and pass freely in the urine... Stone of more than 5 mm require surgical treatment..dont get delay Consult urologist for more suggestions Thank you Dr.siddartha