Working diagnosis is a term used to refer to the leading contender in a list of two or more potential diagnoses. Infrequently, at the conclusion of the initial consultation, we have two fairly strong diagnostic possibilities, and begin with treatment for one of them, now termed the working diagnosis, as the next step in finalizing a diagnosis. If a working diagnosis is relatively certain, we may begin treatment for that diagnosis. In other cases, additional testing is in order to try to solidify the working diagnosis into a final diagnosis.
See also differential diagnosis.