Ureteral stones mostly originate from the kidneys, mostly unilateral stones, and occur more often in middle-aged people, with a higher incidence in men than in women. The causes and composition of stones are similar to those of kidney stones. Stones are commonly found in the following areas: ① The junction of the renal pelvis and ureter; ② The area where the ureter crosses the iliac vessels; ③ The female ureter passes through the base of the broad ligament of the uterus, and the male vas deferens crosses the ureter; ④ The ureteral bladder wall segment including the bladder opening. The main secondary lesions include urinary tract obstruction, infection, epithelial damage, and cancer. Large or rough-surfaced stones are easily embedded in the narrow part of the ureter, causing severe obstruction and renal damage. Severe bilateral ureteral stones can even cause renal failure.