This article is from the Interpretation Of Lab Test Profiles, by Ed Uthman firstname.lastname@example.org with numerous contributions by others.
Because reference ranges (except for some lipid studies) are
typically defined as the range of values of the median 95% of
the healthy population, it is unlikely that a given specimen,
even from a healthy patient, will show "normal" values for all
the tests in a lengthy profile. Therefore, caution should be
exercised to prevent overreaction to miscellaneous, mild
abnormalities without clinical correlate.