Nosology expansion: not always for health’s sake
Bjørn Hofmann outlines and discusses in this journal  six main ways, not mutually exclusive, through which the domain of human disease is expanded, substantively and semantically.
The rationale for nosology building is to provide a basic instrument for disease investigation in medical research and practice; these, in turn, have the substantive objective of disease control and, ultimately, of population health maintenance and improvement. The resulting relation between the latter and nosology expansion is therefore indirect as well as subject to changes in the course of time.
A long-term development
Nosology expansion occurs either by (1) adding newly occurring diseases with distinctive characteristics (e.g. emerging infectious disease like Zika Virus Infections or the Coronaviruses and Acute Respiratory Syndromes)  or (2) splitting an existing disease into finer categories (in fashionable language, into “finer granularity”) or (3) annexingto a known disease some manifestations,...
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