Uric acid is the end product of purine metabolism, mainly produced by the cellular metabolic breakdown of nucleic acids and other purine-like compounds and purines in food by the action of enzymes. When the body 37 ℃ when the saturation and concentration of uric acid is about 420 μmol / L (7mg / dl), more than this concentration is hyperuricemia. High blood uric acid has two main types of causes: increased uric acid production and decreased uric acid excretion, and sometimes the two coexist. Increased uric acid production: mainly including high purine dietary intake and endogenous purine metabolism increased. Food-induced uric acid production is proportional to the purine content of the food, and purine-rich foods mainly include animal liver, kidney, anchovies and so on. The body endogenous purine metabolism increased mainly related to the synthesis and decomposition of purine and other factors. Decreased excretion of uric acid: about 2/3 of uric acid is excreted through the kidneys, and the remaining 1/3 is excreted through extra-renal pathways such as the intestines and biliary tract. About 90% of patients with persistent hyperuricemia have a defect in renal processing of uric acid, which is manifested by reduced uric acid excretion, including reduced glomerular filtration rate, increased tubular reabsorption, reduced tubular secretion, and deposition of urate crystals. Therefore, the exact cause needs to be confirmed by combining the patient’s medical history and relevant examinations.