The main kidney function tests are serum urea, blood creatinine, blood β2-microglobulin, uric acid and several other items. 1.Serum urea (BUN) Serum urea is a metabolite of protein, which is excreted in urine after glomerular filtration in the kidney. Therefore, by measuring serum urea, we can understand the filtration function of the glomerulus. It can be detected when there are diseases in the urinary system, and it can be detected when there are toxic hepatitis and lipid-like nephropathy. 2.Blood creatinine Blood creatinine to a certain extent reflects the filtration capacity of the kidney, but this is a more advanced symptom, and its value is almost unchanged when the kidney function is mildly damaged. When the symptoms of significantly elevated blood creatinine appear, the kidney function has been severely damaged, so it also needs to be combined with other tests for early diagnosis. 3.Blood β2-microglobulin This is a protein produced by lymphocytes, leukocytes and other cells, which is mostly reabsorbed by the kidney. Its value will be increased in cases of renal decompensation, malignant tumors, autoimmune diseases such as systemic lupus erythematosus and other diseases. 4.Uric acid Uric acid is a metabolite of purine, mainly used in the detection of gout, when the presence of gout can be seen in the serum uric acid significantly increased. Some other kidney diseases or malignant tumors may also show an increase in the test value. Kidney function tests are important for clinical diagnosis and detection of lesions in the body.