There is a substance called purine in the body that causes gout when its metabolism is disturbed. Purine undergoes a series of metabolic changes and the final product is called uric acid. Uric acid has no physiological function in the body. Under normal circumstances, 2/3 of the uric acid produced in the body is excreted by the kidneys and the remaining 1/3 is excreted from the large intestine. Uric acid is continuously produced and excreted in the body, so it is maintained at a certain concentration in the blood. In the process of synthesis and decomposition of purine, there are various enzymes involved, and due to the congenital abnormality of enzymes or some factors that have not yet been clarified, the metabolism is disturbed and the synthesis or excretion of uric acid is increased or decreased, which can cause hyperuricemia. When the blood uric acid concentration is too high, uric acid is deposited in the form of sodium salts in joints, soft tissues, cartilage and kidneys, causing a foreign body inflammatory reaction in the tissues, which becomes the bane of causing gout, but increased blood uric acid is not equal to gout. An increase in uric acid in the blood can help in the diagnosis of gout. However, it should be noted that other factors that affect the increase of blood uric acid, such as eating a high-calorie, high-purine diet, hunger and alcohol consumption, the application of diuretics such as thiazides and aminoglutethimide, small amounts of aspirin drugs, etc., can increase uric acid in the blood, so it is not possible to “once determine a lifetime”, that is, once the blood uric acid value increases, then consider suffering from gout. In fact, even if the blood uric acid is increased, it can be asymptomatic hyperuricemia, which can persist for a long time before the appearance of gout symptoms. People with hyperuricemia do not necessarily all develop gout. Of course, the higher the blood uric acid value, the greater the likelihood of developing gout symptoms. In fact, some patients may have increased uric acid excretion from urine due to endogenous hormones during an acute attack of gout, resulting in a blood uric acid value within the normal range, but instead the blood uric acid value increases only after the acute attack has subsided. Therefore, the measured blood uric acid should be analyzed together with the patient’s symptoms, physical signs, X-ray examination and synovial fluid examination for uric acid crystals to make the diagnosis of gout.