In general, the normal level of creatinine in nephritis is 53~106μmol/L for men and 44~97μmol/L for women, the reference range is different in different hospitals, so please follow the level of your local hospital. Its increase and decrease have certain clinical significance. 1. Elevated blood creatinine. It may be related to acute and chronic renal failure caused by glomerular filtration hypoperfusion; it can also identify pre-renal and renal oliguria to a certain extent. Common causes of acute renal failure include heart failure, dehydration, urinary tract obstruction, drug injury, etc. Common causes of chronic renal failure include glomerulonephritis, diabetic nephropathy and hypertensive nephropathy. 2. Reduced blood creatinine. The blood creatinine of the elderly, emaciated people and malnourished people is generally low. When the value of blood creatinine is abnormal, you should consult a doctor in a regular hospital in time, clarify the cause of the disease under the guidance of the doctor, and take active treatment.