When should clinicians use the term syndrome?

Medical language provides essential communication with patients and among healthcare providers. Some words appear frequently in this communication, in clinical records, and in the medical literature, and the use of these words assumes that the listener and reader understand their meaning in the context related to their current use. Words, such as syndrome, disorder, and disease, should have obvious definitions but often, in fact, have uncertain meanings. In particular, the word syndrome should imply a definite and stable association between patient characteristics that have implications for treatment, prognosis, pathogenesis, and possibly clinical studies. In many cases the strength of this association is uncertain and the use of the word represents a convenient shorthand which may or may not improve communication with patients or other clinicians. Some astute clinicians have identified associations in their clinical practices, but this is a slow haphazard process. The development of electronic medical records, internet-based communication, and advanced statistical techniques has the potential to clarify important features of syndromes. However, the recent analysis of certain subsets of patients in the ongoing COVID-19 pandemic has demonstrated that even large amounts of information and advanced statistical techniques using clustering or machine learning may not provide precise separation of patients into groups. Clinicians should use the word syndrome carefully.