Kidney stone pain usually starts in the back, lower back, and then travels down the ureter, possibly to the vulva, perineum, and inner thighs. Kidney stone pain can sometimes be very severe, but it can also vary depending on the type of kidney stone or where it is lodged. When the stone is large, it usually gets stuck in the renal pelvis or kidney and causes urinary retention and hydronephrosis, which is manifested as distending pain or dull pain; when the stone is small and can move freely in the renal pelvis or ureter, it may irritate the ureter and cause spasm of the ureter, which is manifested as colic and the pain is very severe, and it may be accompanied by nausea, vomiting, and sweating profusely.