Serum creatinine, the end product of creatine metabolism, is excreted by the kidneys and is mostly used as an indicator to check the kidney function of patients. The higher value of blood creatinine may be related to physiological and pathological factors: 1. Physiological factors: The slight increase in blood creatinine test than normal may be due to physiological reasons, such as the patient itself is more muscular and stronger, after the intake of excessive exogenous protein, which may lead to the value higher than normal. However, the kidney function of such people is normal, and the value can fall and return to normal after the diet is restored to normal for a period of time; 2. Pathological factors: When the kidney and glomerular metabolic function of patients have problems, it may cause the blood creatinine to rise. Such as acute and chronic glomerulonephritis, diabetic nephropathy, etc. In addition, due to large individual differences, elevated blood creatinine in patients is commonly associated with various causes of acute and chronic renal failure, myocarditis, muscle damage and other diseases in clinical practice. It is not possible to fully judge whether there is abnormal kidney function by blood creatinine alone, and patients are advised to check blood urea nitrogen at the same time. If both are elevated at the same time, it indicates that kidney function is seriously impaired, and the prognosis is usually poor when blood creatinine > 400 μmol/L. If patients have high blood creatinine, they should actively go to the hospital for examination and targeted treatment under the guidance of doctors.