Normal ranges: normal for whom?

Normal ranges: normal for whom?
While the practice of medicine has moved from art to science, laboratory testing has increased in volume. As part of our normal clinical care we often order laboratory tests and use the results, ideally in combination with the history and physical exam findings, to draw conclusions about the health or condition of our patients. Interpretation of laboratory results generally consists of comparing a patient’s lab values to the “normal range”—usually provided by the testing laboratory. Values within the normal range are interpreted as good or normal while those outside the range may indicate disease or the presence of a condition.
Source: fertstert.org