Creatinine 300μmol/L can be seen in acute renal failure, chronic renal failure. In acute renal failure, there is no specific clinical stage; in chronic renal failure, creatinine 300μmol/L belongs to the decompensated stage. Creatinine is a toxin produced by muscle metabolism in the body, mainly by the kidneys to remove, clinically testing creatinine can determine the renal function. The normal value of blood creatinine is 53~106μmol/L for men and 44~97μmol/L for women, and the standard value varies from hospital to hospital, according to the reference value of local hospital test. Most of the blood creatinine higher than normal value represents kidney damage, increased blood creatinine is common in acute or chronic renal insufficiency, etc. Among them, acute renal failure is not clinically recognized. Acute renal failure has no specific clinical stage; chronic renal failure can be divided into four stages according to blood creatinine value. The creatinine value in compensated stage is 133~177μmol/L, the creatinine value in decompensated stage is 177~442μmol/L, the creatinine value in renal failure stage is 451~707μmol/L, and when the creatinine is more than 707μmol/L, it is uremia stage. So chronic renal failure creatinine 300μmol/L belongs to the decompensated stage. Patients with elevated creatinine are recommended to go to regular hospitals in time to improve the relevant examinations and standardized treatment under the guidance of physicians.