In the late twentieth century, impressive achievements have been made both in basic and clinical research on urinary calculi, but clinical practice has been one-sidedly focused on the surgical treatment of urinary calculi while neglecting the prophylactic treatment of stones, which points to the fruit rather than the cause. For this reason, this article emphasizes the metabolic assessment and preventive treatment of urinary stones based on physiological and biochemical factors. 1. Metabolic assessment Most urinary stones are due to metabolic disorders in the human body, therefore, patients can be evaluated by metabolic modalities. The metabolic assessment of patients with urinary stones was originally proposed by Pak in the United States. This method has been refined several times and is still the gold standard for diagnosing the cause of urinary stones. The overall recurrence rate of urinary stones is upwards of 50% within 10 years, so the significance of metabolic assessment is to individualize preventive treatment for the cause of the stones and to focus on those patients who are at higher risk of stone recurrence. Although it is often difficult to predict in advance which patients will recur, in general, two groups of patients have a higher likelihood of stone recurrence: 1) those with multiple stones, recurrent stones, antler-shaped stones, calcium phosphate stones, uric acid stones, ammonium-magnesium phosphate stones, cystine stones, and renal stones in children; 2) those with a family history of urinary stones, chronic enterocolitis, short-circuit intestinal surgery, bone disease, chronic urinary tract infections, and gout. History of gout. The metabolic assessment is classified according to its complexity into three types: simplified assessment; 2. extensive assessment; and 3. specific assessment. The patient’s assessment should be scheduled before or 1 month after treatment so that the accuracy of the assessment is not affected by the patient’s change in diet at one time. The evaluation includes 1) serum tests, including sodium, potassium, chloride, calcium, phosphorus, magnesium, bicarbonate, uric acid, creatinine, parathyroid hormone, and 1,25-dihydroxyvitamin D. 2) urinalysis, including urine routine, urine pH, urine culture, and sodium nitroprusside test. 3) quantitative 24-h urinalysis, including urine volume, sodium, calcium, phosphorus, magnesium, uric acid, oxalic acid, citrate, cystine, creatinine, etc. 4) stone analysis. , stone analysis. The following is a description of the assessment of patients with urinary stones in terms of clinical practicality and convenience, based on the actual situation in China. 1.1. Simplified evaluation Simplified evaluation includes serological examination, urinalysis and stone composition analysis, and is generally used only for patients with stones who have a first episode and are at low risk of recurrence. In serology, elevated parathyroid hormone and calcium are the mainstays of the diagnosis of hyperparathyroidism; decreased bicarbonate, high blood chloride, and low blood potassium are characteristic signs of tubular acidosis; decreased phosphorus is seen in type III absorptive hypercalciuria; and hyperuricemia is an important diagnostic indicator of gout. In urinalysis, persistent acidic urine (pH 7.2, suggests magnesium ammonium phosphate stones; failure to lower pH below 5.5 suggests tubular acidosis; sodium nitroprusside test is used to screen for cystinuria; urine culture detects detoxifying enzyme-producing bacteria, suggesting magnesium ammonium phosphate stones. Stone composition analysis is the most direct way to determine the nature of stones and can provide a basis for developing preventive measures for stones and selecting litholytic drugs. Sample specimens are obtained from stones that have been discharged naturally by the patient, after lithotripsy, or surgically removed. Two types of analysis methods are commonly used: physical analysis and chemical analysis. Infrared spectroscopy can analyze the inorganic and organic components of stones; polarized light microscopy can be used to identify stone components as well as to observe the structure of stones; X-ray diffraction is a reliable means to detect the crystalline phase of stones. The traditional chemical analysis method can be used to determine the ions and chemical groups in stones, but it has been largely eliminated in foreign countries because of its unreliable results and the large amount of specimens needed, especially the small amount of stone powder discharged after shock wave lithotripsy, which often cannot meet the amount of specimens needed for chemical analysis. When analyzing stone composition, it is generally necessary to use both methods in combination to complement each other in order to make the identification results more accurate and complete. For example, if cystine is detected in the stone, the diagnosis of cystinuria can be confirmed; if magnesium ammonium phosphate is detected, the stone can be presumed to be caused by bacterial infection; if pure calcium phosphate stones are found, tubular acidosis should be suspected; when the phosphate content in the stone core is high, the stone is prone to recurrence. When the core of the stone is pure calcium phosphate and the outer layer is calcium oxalate, the stone may be a kidney stone caused by hyperparathyroidism. 1.2. Extensive evaluation Extensive evaluation is a more in-depth evaluation of patients with stones, based on a simplified evaluation with quantitative 24-h urine analysis. The indications for extensive evaluation are 1) patients with primary stones with a high probability of recurrence, 2) all patients with recurrent stones, and 3) patients with suspected potential stone formation after simplified evaluation. 24-h urine quantitative analysis is a key component of extensive evaluation. It is characterized by the collection of 24-h urine and the analysis of metabolites and risk factors in the urine that influence stone formation. Logically, the more days of urine collection, the more reliable the results, but to reduce the financial and time burden on the patient, only two 24-h urine quantification analyses are usually performed, one every other week. In order for the analysis to be accurate, the necessary preparations should be made in advance, with the following process 1. Try to keep the patient on a weekday diet so that the urine sample is taken in a way that accurately reflects the environmental factors that cause stone formation; 2. Various medications that affect the results of the analysis, including antacids, diuretics, calcium preparations, magnesium preparations, vitamin D, vitamin C, allopurinol, and adrenocorticosteroids, should be stopped for 5 days prior to the evaluation; 3. Collect 24-h urine samples (i.e., random dietary urine samples) on two days every other week for separate quantitative analysis; 4. Develop a special restricted recipe for the patient, i.e., calcium restriction.