Drinking plenty of water to keep the concentration of stone matrix in the urine below saturation and to prevent its precipitation is the most important and effective preventive measure for all types of stones. It is economical and inexpensive, and it is very effective to keep the volume of urine above 2,000 ml per day, and to keep the urine diluted at night with a glass of water, especially at night before going to bed. However, for patients who sleep poorly at night, it is necessary to weigh the pros and cons and implement it at one’s own discretion. For patients who can identify the composition of the stones, there are relatively targeted preventive measures according to the composition of the stones. Urologic stones calcium oxalate stones eat less spinach. In urinary stones, calcium oxalate stones accounted for 70% to 80%, therefore, in the diet, in addition to drinking more water, to prevent calcium oxalate oversaturation, and calcium oxalate crystals flushed out, but also try to eat less spinach. Because spinach is rich in calcium oxalate. Uric acid stones: eat less high-purine foods Although patients with uric acid stones may not always have gout, and patients with gout may not always have uric acid stones, a portion of urinary stones do have stones caused by high uric acid. Uric acid stones are prevented in the same way that gout is prevented. In terms of diet, it is important to avoid high purine foods. For example, red meat, offal, seafood, beer, red wine, and old-fashioned soup are all high-purine foods. Infectious stones: controlling infections Many of the female patients with urinary stones are caused by urinary tract infections. As a result of urinary tract infection, the urease enzyme produced can catalyze the decomposition of urea into ammonia and carbon dioxide, and ammonia is then combined with water to form ammonium hydroxide. When the urine pH reaches 7.2, ionized ammonium can combine with magnesium and phosphate in the urine to form magnesium ammonium phosphate. When the magnesium ammonium phosphate in the urine reaches a supersaturated level, crystals are precipitated. However, these crystals adhere to the epithelium of the urinary tract and, over time, form stones. This type of urinary stone has a high recurrence rate, up to 50% within a year if left unchecked. Therefore, infected stones, in addition to replenishing enough water, but also to find out what bacterial infection is caused by the symptomatic medicine, control the infection. Only then can we effectively prevent recurrence. Pediatric cystinuric acid stones: control protein intake There is another category of urinary stones belonging to pediatric cystinuric acid stones, which is a kind of hereditary stones. All substances containing amino acids have the potential to form cystinosis. With this type of stone, the child usually develops them at an early age and they tend to recur. Theoretically, the patient must control protein intake and eat only fruits and vegetables, but this in turn affects the child’s physical development. Therefore, patients can only be controlled medically when they are minors, and dietary control is only possible when they are adults.