In China, urolithiasis is one of the three most common diseases in urology, with a prevalence of 1-10%, second only to benign prostatic hyperplasia and urinary tract infections. About 25% of these patients require hospitalization, ranking first among urological inpatients. At the same time, stones are prone to recurrence after treatment, with a 10-year recurrence rate of up to 50%. The incidence of urinary stones is still on the rise. As the old saying goes, “The top doctor treats the disease that is not yet sick, the middle doctor treats the disease that will be sick, and the bottom doctor treats the disease that is already sick.” Therefore, how to achieve the maximum prevention of urolithiasis is particularly important, which most of us can do is to prevent through diet and nutrition. It is well known that drinking water is very effective in the prevention of urolithiasis. Drinking more water can increase the volume of urine (which should be kept at 2000-3000ml per day) and significantly reduce the saturation of urinary stone components (especially calcium oxalate). According to statistics, a 50% increase in urine volume can reduce the incidence of urinary stones by 86%. The peak of excretion is 3h after a meal, and it is even more important to maintain sufficient urine volume. Drinking water before going to bed makes the relative density of urine (specific gravity) at night lower than 1.015. Drinking more water can produce a certain pressure in the proximal segment of the urinary tract of stones, which can promote the discharge of small stones; it can dilute excretion and some substances related to stone formation (such as TH protein). However, it is also believed that drinking large amounts of water also dilutes the concentration of inhibitors in the urine, which is detrimental to the prevention of stone formation. In fact, supersaturation of urine plays a very important role in the influence of urinary stone formation; in contrast, drinking large amounts of water has a much smaller effect on the reduction of inhibitor concentrations. However, it is worth noting that in some cases, excessive drinking can disrupt electrolyte disturbances in the body, as is often the case in marathon runners, who drink excessive amounts of water after sweating profusely. Therefore, in such cases it is necessary to mix some electrolytes and sugars in water, such as chicken broth, coconut water, electrolyte water or oral rehydration salt solution. It is important to mention that artificial sweeteners are not suitable at this time, because this will instead aggravate the dehydration state. Some studies have concluded that green tea can prevent the formation of calcium oxalate stones. Green tea contains 13% catechol (catechin), which has an antioxidant effect and can reduce the excretion of oxalic acid in the urine and the formation of calcium oxalate precipitates. Therefore, when choosing beverages you can choose green tea beverages, and what you need to avoid are sugary drinks, such as fruit juices and sports drinks, because they increase the calorie intake as well as alter the acid-base balance in the urine. For most patients with urinary stones, urine needs to be kept weakly acidic, and one of the ways to do this is to add citrate to the water, of which lemon juice and lime juice are more appropriate. In addition, studies have shown that obesity increases the risk of water deficiency, so it is necessary to control the diet and increase exercise to lose weight, rather than through laxatives and excessive dieting, which can be counterproductive and increase the risk of developing urolithiasis. Recent studies have found that modifications in diet and nutrition can help prevent the formation of urolithiasis. The specific modifications need to be based on the results of the urinary stone composition analysis and the morphology of the stones on radiographs to determine the composition of the stones and to develop preventive measures. 1. Calcium oxalate stones. They are the most common, accounting for 71% to 84%. The stones are spherical, oval, rhombus or mulberry-shaped, dark brown, very hard, rough surface, so it is easy to damage the tissue and cause hematuria, mostly seen in acidic urine. Therefore, the formation of these stones can be prevented by adjusting the diet and nutrition to reduce the acidity of the urine. Nutritional supplements include potassium citrate, potassium magnesium citrate, and calcium citrate. If urinary calcium levels are high, limiting sodium intake to no more than 2 g/day can help prevent the formation of urolithiasis. It is also necessary to avoid excessive protein intake, too much or too little vitamin D in the diet. 2, uric acid stones. They account for 5% to 10% of cases. Stones are round or oval, smooth surface, orange-red, hard, radially arranged in the cut surface, easy to occur in acidic urine. Therefore, improving the PH of urine is an important method to prevent uric acid stones, of which drinking orange juice is a recommended method. A study proved that drinking 1200ml of orange juice daily, equivalent to taking 60mmol of potassium citrate, can increase the urinary PH from 5.7 to 6.5. at the same time, the urinary citrate content increased from 571mg/d to 952mg/d. Meanwhile, controlling the intake of protein and sugar and reducing the intake of alcohol also have a certain preventive effect. 3. Calcium phosphate stones. Account for 6-9%, mostly seen in women during pregnancy, granular stones, gray-white, in alkaline urine can rapidly increase, but simple rare, mostly mixed with calcium oxalate or ammonium magnesium phosphate into stones, often forming antler-shaped stones. Therefore, adjusting the diet to improve the acidity of the urine can prevent the formation of calcium phosphate stones, and its low-calcium diet is the same as calcium oxalate stones. Eat more low-phosphorus food, it is advisable to eat less meat, fish and bone broth. 4. Cystine stones. They account for about 1% of the total number of stones, mostly seen in children. The stones are yellowish, with a smooth surface and soft texture. These stones are mostly due to overly acidic urine. The dietary adjustment is the same as uric acid stones. 5. Infectious stones. They are often associated with bladder infections and form antler-shaped stones. Increasing the intake of water as well as fruits, vegetables, grains, nuts and tea can help to reduce the occurrence of bladder infections and thus prevent the formation of these stones. Therefore, in general, in order to prevent the formation of urinary stones, we need to pay attention to the following things: drink more water, take fiber and vitamin A and vitamin B6 supplements, control the intake of calcium, salt, protein, sugar, vitamin C and vitamin D, reduce the intake of foods rich in oxalates and other foods that contain the main components of stones, as well as increase exercise and maintain a regular diet and lifestyle. I believe that the adjustment of diet and nutrition can reduce the occurrence of urolithiasis and keep away from the pain caused by urolithiasis, thus improving people’s quality of life.