General Science



  • The process of determining the causes of a given malfunction. There are various diagnostic resources, such as tests, to help in this task.

Health Economics

  • (written as Diagnosis)
    The attaching of a disease label to a patient's (or family's or larger group's) condition after examining symptoms and performing various tests.

Information & Library Science

  • noun the act of identifying the reason for a fault or problem


  • noun the act of diagnosing a condition or illness

Origin & History of “diagnosis”

The underlying meaning of Greek diágnōsis was ‘knowing apart’. It was derived from diagignṓskein ‘distinguish, discern’, a compound verb formed from the prefix dia- ‘apart’ and gignṓskein ‘know, perceive’ (a relative of English know): In post-classical times the general notion of ‘distinguishing’ or ‘discerning’ was applied specifically to medical examination in order to determine the nature of a disease.