Blood creatinine is a very important indicator of renal function test, which is usually obtained by fasting blood test. Creatinine, in the clinical often have two units, are umol / L and mg / dL, generally speaking 1mg / dl = 88.4umol / L, 1mg / L = 0.0884umol / L. This conversion is relatively simple. Elevated blood creatinine is often indicative of renal insufficiency. At this time, it is necessary to go to the hospital for timely consultation to determine the cause of renal insufficiency, whether it is a primary kidney disease or secondary kidney disease. Primary renal disease is often seen in glomerulonephritis, while secondary renal disease is most commonly seen in high kidney disease and diabetic nephropathy.