Why Understanding A Reference Range is Important

   Every time a laboratory does a test the results are shown with something called a reference range so the doctor can tell if the results are abnormal or not.  If your result is within the reference range your doctor usually will consider your results to be OK.  If your lab test result is below or above the reference range shown then your doctor may want to do additional testing.   For example, if the reference range for a test is 50 - 100 mg/dL and your result is 40 mg/dL then your result would be considered "below" the reference range and your doctor may want to do additional testing to verify the results. 

A good discussion of reference ranges and their clinical utility can be found at the American Association for Clinical Chemistry's Labtestsonline Website.