Urinary stones are a general term for kidney stones, ureteral stones, bladder stones and urethral stones, which are very common urological diseases. Their epidemiology and etiology are summarized as follows: 1. Epidemiological factors: (1) gender and age: the incidence of urolithiasis in the population is about 2-3%. Recurrence occurs in about 1/3 of patients within 5 years after treatment of renal calculi. Men and women are 31, and women are prone to infected stones. In China, the proportion of men and women with upper urinary tract stones is similar, and men have significantly more lower urinary tract stones than women,. Urolithiasis occurs between the ages of 25-40 years. few people suffer from urolithiasis before the age of 20. In children, it occurs mostly between 2-6 years of age and is often associated with malformation, infection, and malnutrition. There are two peaks in women, between 25-40 and 50-65 years of age. In men, urolithiasis in the elderly is associated with urinary tract obstruction due to prostate enlargement, which can secondary to bladder stones. Li Qi, Department of Urology, Xiyuan Hospital, Chinese Academy of Traditional Chinese Medicine (2) Race: The incidence of urolithiasis is related to race, and the annual incidence of urinary calculi in the United States is 1.64%. The annual incidence of urinary calculi in the United States is 1.64%. Fewer people of color suffer from urolithiasis than whites. (3) Occupation: Some data show that occupation is associated with the incidence of urolithiasis, such as people who work in high temperature, pilots, seamen, surgeons, office workers, etc. The prevalence of kidney stones among Air Force pilots is 3.5-9.4 times higher than that of ground personnel. (4) Geography and climate: There are significant regional differences in the incidence of urolithiasis. The prevalence of urolithiasis is higher in mountainous, desert, tropical and subtropical regions, which is mainly related to environmental factors such as dietary habits, temperature, and temperature. In the south of China, urolithiasis is the most common disease in patients seen in urology, while it accounts for only 10-15% in the north. (5) Diet and nutrition: the composition and structure of the diet have an important impact on the formation of urinary stones. Some data show that a large intake of animal protein and refined sugar in the diet can increase the risk of upper urinary tract stone formation. Others such as fat, heyling, oxalic acid, calcium, phosphorus, trace elements, and vitamins can affect the formation of urinary stones. When the nutritional status is good and the intake of animal protein is too much, it is easy to form kidney stones, the main component is calcium oxalate and calcium phosphate; when the nutritional status is poor and the intake of animal protein is too little, it is easy to form bladder stones, the main component is uric acid. In China, due to the socio-economic development and improvement of living standard, the diet structure has changed and the nutritional status has been improved, the incidence of upper urinary tract stones is now much higher than that of lower urinary tract stones, especially bladder stones in children have been rare. (6) Water intake: Any factor that disrupts the balance between water intake and loss, such as excessive sweating, will increase the over-saturation of calcium and salt in urine, which is conducive to the formation of urinary stones. Conversely, drinking large amounts of water to make urine dilute sticks can reduce the formation of crystals in urine. (7) Disease: The formation of some urinary stones is related to hereditary diseases, such as deaminuria, familial xanthinuria, etc. The formation of urinary stones is often familial and genetic mutations associated with it have been found. Congenital malformations such as polycystic kidney, hoof-shaped kidney, pelvic ureteral junction obstruction (UPJO), medullary spongy kidney and lower urinary tract malformation are also closely associated with urolithiasis formation. Metabolic disorders such as hyperparathyroidism, hyperuricemia and hyperoxaluria, as well as urinary tract obstruction and infection are also factors in the formation of urinary calculi. 2. Urinary changes: (1) Increased excretion of substances that form urinary stones: increased excretion of calcium, oxalic acid or uric acid in urine. Increased urinary calcium in people who are bedridden for a long time and hyperparathyroidism; increased uric acid excretion in gout patients; increased endogenous synthetic oxalic acid or increased intestinal absorption of oxalic acid causing hyperoxaluria, etc. (2) Change in urinary pH: in alkaline urine, ammonium magnesium phosphate and phosphate precipitates are easily formed; in acidic urine, uric acid and cystine crystals are easily formed. (3) Decrease in urine volume, which increases the concentration of salts and organic substances. (4) Decrease in substances that inhibit crystal formation and aggregation in urine, such as citrate, pyrophosphate, acidic mucopolysaccharide, magnesium, etc. (5) Increased urinary matrix in urinary tract infection, which causes crystals to adhere. Some bacteria such as Escherichia coli can decompose urea to produce ammonia, so that urine pH ≥ 7.2, easy to form magnesium ammonium phosphate stones. 3, abnormalities in the anatomical structure of the urinary tract some believe that the subepithelial calcified spots of the renal papillae are foci of stone formation, which can cause oxalate, phosphate and uric acid crystals to precipitate. Stenosis, obstruction, diverticulum in any part of the urinary tract can make urine retention, leading to the formation of crystals or matrix deposits in the area, and urine retention secondary to urinary tract infection is conducive to stone formation.