- Date: 1655
- b : the decision reached by diagnosis
- 2 : a concise technical description of a taxon
- 3 a : investigation or analysis of the cause or nature of a condition, situation, or problem <diagnosis of engine trouble>
Diagnosis (Greek: διάγνωση, from δια dia- "apart-split", and γνώση gnosi "to learn, knowledge") is the identification of the nature of anything, either by process of elimination or other analytical methods. Diagnosis is used in many different disciplines, with slightly different implementations on the application of logic and experience to determine the cause and effect relationships. Diagnosis also is used in many other trades and professions to determine the causes of symptoms, mitigations for problems, or solutions to issues.