Blood creatinine over 100 μmol/L is not serious. Creatinine is produced by the body’s metabolism and is excreted from the body mainly through the kidneys with urine. Clinical assessment of renal function is generally done by testing the level of blood creatinine. Our traditional staging method of renal decompensation is based on the blood creatinine level. Blood creatinine in the range of 133-177 μmol/L belongs to the decompensated stage of renal insufficiency. Elevated blood creatinine can be seen in various primary or secondary glomerular diseases, and active control of the primary disease can help protect renal function. Patients with glomerulonephritis should effectively control proteinuria, which can slow down the progression of renal function. Diabetic nephropathy and hypertensive kidney damage, strict control of blood pressure and blood sugar can also help protect kidney function.