Common Sense of Serum Creatinine

People should see a doctor for an overall examination if there is something wrong with their kidneys, and the test report may show your serum creatinine is high, and then doctor may say there must be some problems in your kidneys. We feel doubtful about a series of indexes on the laboratory sheet, so what is the normal range of serum creatinine?

I What is serum creatinine?
The word "serum creatinine" is difficult to understand for many patients. In fact, serum creatinine is the break-down products of muscle metabolizing. Creatinine is formed slowly in human muscles by creatine’s irreversible nonenzymic dehydration reaction. It will be released into blood and finally discharged outside the body though urine. The kidneys own the functions of filtration and excretion, so there is a closed relationship between kidneys and creatinine. For healthy people, the creatinine will be discharged from the urine instead of being absorbed by kidney tubules. Clinically, serum creatinine test is one of the main methods that is commonly used to diagnose kidney function.

II What's the normal range of serum creatinine?
The reference value of serum creatinine varies from different regions and different hospitals. Generally speaking, the range of reference value of serum creatinine is between 44-133 umol/L, which means that kidneys have been damaged when the value of serum creatinine is higher than 133 umol/L.

III Why serum creatinine increases?
Due to the closed relationship between serum creatinine and kidneys, so the value of serum creatinine reflects damaged situation of renal parenchyma exactly. In most situations, different serum creatinine value means that your kidneys are damaged in different degrees. We should understand that the metabolic capacities of human kidneys are strong. We won’t feel discomfort obviously when the kidneys are damaged slightly. The kidneys have already been damaged seriously once we feel physical abnormalities, such as vomiting, puked or dizzy. Therefore, the serum creatinine will still be normal in the early-stage kidney disease or kidneys are damaged slightly. There will be an obvious increase of serum creatinine concentration when the filtration function drops to the one-third of healthy person. So we say that increase of serum creatinine means serious damage of kidneys.
Patients want to lower their creatinine level but the more important thing they should care about is their kidney function, we hope everyone can know that creatinine will not be high if there is no damage on kidney, so repair damaged kidneys is primary thing for them. If we do not want to disease relapses, treating kidneys fundamentally.