Abstract
Laboratory examinations are part of the diagnostic-therapeutic process. They play an important role in the decision how to proceed in acute and chronic diseases and in their monitoring.
Obvious changes can be seen in organ damage, and generally, the more severe the damage, the more expressed are the changes. On the other hand, there are also cases when the patient is not feeling well but the results are so called normal or almost "normal", i.e. correctly described in the reference range.
The aim of the work was to consider what the results in reference ranges can mean. Reference range contains 95 % of population, i.e. 5 % of healthy subjects will have results out of this range and will be false positive.
On contrary, some patients can have results in this range and be false negative. A patient who is not feeling well but the changes in the laboratory results are only discrete if any (everything in reference range or boundary results) is not necessarily healthy.
Laboratory results have to be interpreted individually in line with the case history, clinical state and results of other examinations. Trends should be followed up as well.
These patients may represent just a minority but they should deserve attention.