The test for uric acid refers to the test for serum uric acid. Normal adult uric acid concentrations range from 150-416 μmol/L in men and 89-357 μmol/L in women, and are produced mainly from purine metabolites in nucleoproteins and nucleic acids. Uric acid can pass freely through the glomerulus and can be excreted through the tubules, but about 90% of the uric acid that enters the primary urine is reabsorbed in the tubules back into the blood. Therefore, the blood uric acid concentration is influenced by glomerular filtration and tubular reabsorption. If one can strictly abstain from purine-rich food for three days and exclude exogenous uric acid interference before blood collection, the change of blood uric acid level is more meaningful.