10 mm stone in the ureter have very minimal chance of spontaneous passage and more chances of causing recurrent pain , swelling in ureter(hydronephrosis), infection and varying degrees of renal damage depending on degree of obstruction and infection hence potentially dangerous to cause kidney dysfunction. Since it is preventable in the era of minimally invasive surgery,it is advised to get complete evaluation by a urologist and get it removed to avoid potential harmful effects in the kidney&body