<s>[INST] i went to the ER in october with  pain in my right side. they did a CT scan nd told me i have a 3mm kidney stone in my right kidney in the lower pole calyx. i have not had any pain since tht day. the pain wasnt even tht bad then for a stone to have passed. i had a stone 10 years ago so i know the pain i should be going through. but i havent had any pain yet. so my question is why hasnt it passed yet whats taking so long. [/INST] Hi,Thanks for writing in.The location of the stone is such that it is not in direct communication to allow its passage. However you need not worry because a 3 mm stone is small and does not necessarily cause any obstruction. The stone being in lower pole is one of the reasons for it not getting passed due to anti gravity. Since thee calyx at lower pole is inclined upwards, such a stone will usually not climb into the renal pelvis and get drained on its own. If it is stable since ten years then you need should not worry. </s>