The normal reference value of creatinine is 53~106μmol/L for men and 44~97μmol/L for women , which may vary slightly from laboratory to laboratory. Creatinine 300μmol/L indicates a more serious renal failure, whether it will affect the life expectancy according to the cause of elevated creatinine, can not be generalized, the life expectancy can range from a few days to decades. 1. Acute renal failure: If the patient is suffering from acute renal damage and the duration of the disease is within three months, after active treatment and removing the factors that cause acute renal damage, the creatinine is very likely to return to the normal range, which will not affect the life expectancy. 2.Chronic renal failure (1) If the patient belongs to chronic kidney damage, also known as chronic renal insufficiency, creatinine 300μmoI/L is more serious, the patient may have swelling, anemia, renal hypertension, and in severe cases, pulmonary edema, heart failure and other diseases. (2) Patients need to strictly follow the doctor’s instructions for treatment, such as diuresis to reduce swelling (furosemide), controlling blood pressure (nifedipine extended-release tablets), correcting anemia (roxarestat), and so on, and in severe cases, dialysis treatment is needed. (3) If the patient is old, combined with heart failure, hyperkalemia, and the primary disease is vasculitis, systemic lupus erythematosus, etc., and the treatment is not timely, he/she may die in a few months or even a few days; if the patient is young, has no other complications, and the primary disease is chronic glomerulonephritis, and the treatment is timely, he/she may survive for decades. Patients with elevated creatinine are advised to consult regular hospitals in time and standardize their treatment under the guidance of physicians.