A high blood creatinine of 12μmol/L may be due to physiological reasons, such as high protein diet or strenuous exercise, which is generally not serious and can be reviewed regularly; it may also be due to pathologic reasons, such as acute and chronic renal insufficiency, with common causes such as drug damage, urinary tract obstruction and glomerulonephritis, which is generally more serious. Physiological causes such as high protein diet, strenuous exercise, muscular athletes, can appear in the blood creatinine elevation, at this time is generally not serious, no drug treatment, light diet, regular review can be. Chronic renal insufficiency can be characterized by elevated blood creatinine levels, common causes include diabetic nephropathy, hypertension, glomerulonephritis and other diseases. This type of disease is more serious, and the disease can develop progressively, and may eventually develop into uremia, requiring renal replacement therapy. Acute renal insufficiency can be divided into three categories: pre-renal acute kidney injury, including dehydration, heart failure and other diseases; post-renal acute kidney injury, including double kidney stones, renal papillary necrosis, bladder cancer and other diseases; renal diseases are mainly seen in acute interstitial nephritis, renal transplantation rejection, etc., such diseases are also more serious, need timely standardized treatment, treatment is not timely, the condition may be aggravated. In conclusion, patients with high blood creatinine 12μmol/L should go to the regular hospital in time to find out the reason, so as not to delay the condition.