Blood uric acid and cystatin C are two different tests. High blood uric acid may be due to excessive production of uric acid, impaired excretion of uric acid, or blood or kidney disease, while high cystatin C may be due to kidney damage. Uric acid is the end product of purine metabolism. Primary or secondary causes may lead to elevated uric acid, broadly including consumption of excessive high-purine diet, alcohol consumption, enhanced nucleic acid metabolism or increased erythropoiesis, hemolytic anemia, acute and chronic leukemia, lymphoma, renal tubular lesions, etc. High uric acid may lead to gout, gouty nephropathy, gouty stones, and other complications in patients. Cystatin C is a specific and sensitive laboratory indicator that can be used to reflect glomerular filtration function. Elevated cystatin C usually indicates that the patient’s renal function is impaired, and once found that the cystatin C is elevated, it is necessary to further improve the blood creatinine, urinary protein and other related tests. In addition, elevated cystatin C is also associated with hyperhomocysteinemia, liver disease and cardiovascular disease. Test results should be interpreted by a professional physician, and patients are advised to go to the rheumatology and immunology department, nephrology department and other related departments in regular hospitals for detailed consultation and not to make judgment on their own.