In medicine, laboratory diagnostics is the examination and analysis of body fluids and excretions. This is done using various optical, immunological or chemical analysis methods. The performance of laboratory diagnostics is often already automated. Body fluids that are regularly examined in the laboratory are blood, serum, cerebrospinal fluid and semen. Body excretions to be examined include urine, sputum and stool. Laboratory diagnostics are used to detect diseases and / or to follow their progress. In addition, laboratory values can be used to prove the effectiveness of therapies. A comprehensive analysis focuses not only on laboratory values that have changed or do not correspond to the norm, but also on how they are related to each other. This is because the constellation of many values can lead to relevant conclusions about chronic diseases – even if the values are within the normal range.
Genetic and molecular biological tests are another important area of investigation.