Checking kidney function requires blood sampling, and the test items are usually blood creatinine, urea nitrogen, etc. You can also understand kidney function through urine test. The main function of kidney is to produce urine, excrete metabolic waste such as urea, creatinine and so on, in order to maintain the water, electrolyte and acid-base balance of the body, and at the same time, secretion of erythropoietin, active vitamin D and so on. The common tests for kidney disease are urine test and blood test for kidney function. Urine test includes urine volume, pH, urine specific gravity, urine protein, leukocyturia, erythrocyturia, etc. to assist in the diagnosis of urinary tract infection, stone, glomerular disease, etc.. Renal function tests include blood creatinine, urea nitrogen, blood uric acid, cystatin C, etc. to assist in the diagnosis of renal diseases and adjustment of medication regimen, etc. Patients with abnormal renal function should go to the hospital in time for consultation and timely treatment under the guidance of professional physicians.