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. High serum uric acid has two main causes: increased uric acid production, decreased uric acid excretion, and sometimes both. When there is an increase in uric acid production: this includes both high purine dietary intake and increased metabolic production of endogenous purines. Food-induced uric acid production is proportional to the purine content of the food, and purine-rich foods mainly include animal liver, kidney, anchovies, etc. The increased metabolic production of endogenous purines in the body is mainly related to the synthesis and decomposition of purines, such as after radiotherapy for patients suffering from psoriasis and tumors. When uric acid excretion is reduced: about 2/3 of uric acid is excreted through the kidneys and the remaining 1/3 through extrarenal pathways such as the intestine. About 90% of patients with persistent hyperuricemia have defects in renal handling of uric acid and show reduced uric acid excretion, including reduced glomerular filtration rate, increased tubular reabsorption, reduced tubular secretion and urate crystallization deposits. Decreased uric acid excretion can be caused by uremia, hypertension, starvation ketosis, acidosis (lactic acidosis, diabetic ketoacidosis), lead poisoning, beryllium poisoning, hypothyroidism, hyperparathyroidism, and certain drugs or substances (e.g., small doses of aspirin, diuretics). Alcohol can both increase uric acid production and decrease uric acid excretion. Therefore, in general, high serum uric acid is mainly caused by two main reasons: increased uric acid production and decreased uric acid excretion, and prompt medical attention is required to find the cause in order to finally confirm the diagnosis.