The damage caused by urinary stones is mainly in the urinary system, which can cause urinary tract obstruction, infection and injury. Stones, obstruction and infection are mutually beneficial, forming a vicious circle, i.e. stones cause obstruction, obstruction causes infection, and infection causes stones. (1) Obstruction The most likely to cause obstruction is ureteral stones, such as stones embedded in the ureteral junction of the renal pelvis, can cause hydronephrosis. If the stone is obstructed in the middle or lower ureter, it can lead to ureteral dilatation and fluid accumulation above the stone. If the stone is located in the renal calyces, it does not necessarily cause significant obstruction and may not cause symptoms. Long-term development of stone obstruction may cause enlargement of the renal pelvis and calyces, hydronephrosis, and eventually atrophy of the renal cortex into a water sac and loss of function. Intermittent or persistent obstruction of the urethral orifice by bladder stones can cause thickening of the bladder wall and urinary retention. If urinary retention persists for a long time, it can cause uremia. (2) Infection Stones combined with infection can cause pyelonephritis, pus accumulation, perinephritis, perinephric abscess, and eventually complete destruction of the renal parenchyma. In addition, obstruction and infection increase the size of the stone and aggravate the kidney lesion. The most common germ of kidney infection is E. coli. (3) Injury Stones can directly cause damage to the kidney and bladder. Larger or rough surface stones can easily cause mucosal erosion, ulceration and bleeding in the kidney or bladder, and even cause spontaneous renal rupture and renal fistula. Long-term irritation of the mucosa by stones may cause squamous epithelial carcinoma, such as renal pelvis cancer and bladder cancer. Therefore, if you have urinary stones, you must actively treat them.