What causes renal colic?

Renal colic is primarily caused by the passage of a kidney stone. When a kidney stone travels through the ureter, it can cause intense pain as it obstructs the urinary tract. This obstruction stimulates a reaction where the smooth muscles in the ureter contract in an attempt to move the stone along, leading to severe and intermittent pain, commonly referred to as renal colic. The pain typically originates in the flank and may radiate to the lower abdomen or groin, depending on the stone’s location.

While inflammation of the bladder, urinary tract infections (UTIs), and prostate issues can cause discomfort and pain in the urinary tract, they do not specifically result in the characteristic severe pain associated with renal colic. Instead, these conditions can lead to different symptoms such as frequent urination, burning sensations, or lower abdominal pain, which are not the same as the acute and spasmodic pain from a kidney stone's passage. Therefore, the most accurate and direct cause of renal colic is indeed the passage of a kidney stone.