Creatinine 400 μmol / L does not necessarily affect life expectancy, depending on the cause of creatinine elevation, which can be categorized into acute elevation and chronic elevation. 1. Acute elevation of creatinine: when creatinine rises sharply in a short period of time, it may be caused by acute diseases. If the cause of acute diseases is actively solved, it usually does not affect the life expectancy, and the creatinine will be reduced to the normal value or the original level after the treatment is finished. 2. Chronic increase of creatinine: When creatinine value is changed for a long time due to chronic kidney disease, it will affect the life expectancy. According to China’s CKD staging, creatinine 400μmol/L indicates that the renal function is in the stage of decompensation, and the renal function has been damaged, which is irreversible change. However, it is possible to delay the renal failure and prolong the life span through active treatment. When creatinine 400μmol/L, you should go to the hospital in time to clarify the cause of the disease and then treat it as soon as possible, so as to avoid irreversible damage to kidney function and delay the condition.