High blood uric acid has two main causes: increased uric acid production, decreased uric acid excretion, and sometimes both. Increased uric acid production: It mainly includes high purine dietary intake and increased endogenous purine metabolism. Food-induced uric acid production is proportional to the purine content of food, and purine-rich foods include animal liver, kidney, anchovies, etc. The increase of endogenous purine metabolism in the body is mainly related to the synthesis and decomposition of purine. Decreased uric acid excretion: About 2/3 of uric acid is excreted through the kidneys, and the remaining 1/3 is excreted through extrarenal pathways such as the intestinal tract and biliary tract. About 90% of patients with persistent hyperuricemia have defects in renal processing of uric acid and show reduced uric acid excretion, including reduced glomerular filtration rate, increased tubular reabsorption, reduced tubular secretion and urate crystallization. Uric acid is the end product of purine metabolism and is mainly produced by the enzymatic breakdown of nucleic acids and other purine compounds from cellular metabolism and purines from food. The saturation and concentration of uric acid in the body at 37°C is about 420 μmol/L (7 mg/dl), and exceeding this concentration is considered hyperuricemia. Therefore, high blood uric acid is mainly caused by two main reasons: increased uric acid production and decreased uric acid excretion, but the specific cause needs to be examined in conjunction with the patient’s medical history and specific condition.