There are kidney stones that do not hurt. Not all kidney stones produce significant pain, only when the kidney stones cause obstruction of the renal pelvis outlet producing hydronephrosis, which can cause more significant pain. If the kidney stone is not in the obstruction area, it will not affect the urinary excretion of the kidney and will not produce painful symptoms, such as stones in the renal calyces or stones in the lower pole of the kidney, which will not affect the outlet of the ureter of the renal pelvis and will not cause hydronephrosis, so it will not produce any painful symptoms. Kidney stones can also be painful if they are infected, but if they are not infected, they can be painless or only mildly painful. The best way to evaluate is to perform a CT scan of the kidney, which can clarify the size of the stone and the distribution of the stone can be clearly seen through the CT film. If surgery is needed, the CT scan can be used to select the access point to break up the stone and remove it as much as possible.