The reasons for the formation of stones are complex, can be broadly divided into individual factors and environmental factors. (A) individual factors 1, metabolic abnormalities Most of the urinary stones are metabolic products of the human body, different components of the stones can reflect the corresponding components of the body’s metabolic abnormalities. The common stone-forming components in urine are calcium, oxalic acid, uric acid and cystine, etc. Any physiological disorders caused by high concentration of these substances in the urine may form stones. The stones formed are (1) Calcium oxalate stones: mainly associated with hypercalciuria, hyperoxaluria, hyperuricosuria, and hypocitraturia. (2) Calcium phosphate stones: mainly caused by alkaline urine due to elevated urine PH. (3) Uric acid stones: mainly due to the lowering of urine PH and acidic urine. The common cause is gout. (4) Cystine stones: cystinuria is its only cause. It is mainly caused by acidic urine. 2, local factors The stones caused by local factors in the urinary system are mostly secondary stones. (1) urinary tract infection: infection is easy to make the urine PH value rise, easy to form magnesium ammonium phosphate and carbonate apatite. The formation of this kind of stone is related to a kind of deconjugating enzyme broken down by Aspergillus. (2) urinary tract obstruction: urinary tract obstruction is easy to make the urine concentration, stone-forming material deposition, the formation of stones. Common diseases include: renal pelvic ureteral junction stenosis and prostatic hyperplasia. (3) Foreign body in the urinary tract: foreign body can act as a core to attract the deposition of stone-forming substances and form stones. (B) environmental factors 1, climate High temperatures, high humidity, the human body through sweating and breathing loss of water increases, urine concentration, easy to form stones. Long sunshine, increased intestinal absorption of calcium, increased urinary calcium, easy to form stones. 2, diet (1) water: urine volume is less than 1000ml per day, the chances of crystal formation in the urine increased significantly, urine volume is less than 500ml, the chances of stone formation increased. (2) Protein: high protein diet is easy to cause hypercalciuria and hyperuricosuria. (3) Calcium: excessive calcium intake can cause hypercalciuria. (4) Vitamins: people who lack vitamins A and B6 are more likely to suffer from calcium oxalate stones. 3, drugs (1) glucocorticoids, can make bone decalcification lead to hypercalciuria. (2) Vitamins: people who take vitamin C and vitamin D for a long time are prone to stones. (3) Sulfonamides: some sulfonamides, easy to form insoluble acetyl compound crystals (drug crystals) in acidic urine or direct formation of sulfonamide stones itself.