High uric acid levels are caused by increased uric acid production and decreased uric acid excretion. Uric acid is the end product of purine metabolism in the body. A long-term high-purine diet will lead to elevated blood uric acid levels; if uric acid excretion is abnormal it will also lead to elevated uric acid levels. Food-induced uric acid production is proportional to the purine content of the food. Purine-rich foods mainly include animal liver, kidney and anchovies. About 2/3 of uric acid is excreted through the kidneys, and the remaining 1/3 is excreted through extra-renal routes such as the intestines and biliary tract. About 90% of patients with persistent hyperuricemia have a defect in renal processing of uric acid and exhibit reduced uric acid excretion. Chronic elevated uric acid levels may lead to hyperuricemia or gouty arthritis, kidney damage, and therefore should be treated as early as possible. Patients with elevated uric acid levels are advised to seek prompt medical attention to avoid delays.