- Rhymes: -ɒlədʒi
- (medicine) The branch of medicine concerned with the study of the nature of disease and its causes, processes, development, and consequences.
- (clinical medicine) The medical specialty that provides microscopy and other laboratory services (e.g., cytology, histology) to clinicians.
- The surgeon sent a specimen of the cyst to the pathology department for staining and analysis to determine its histologic subtype.
- Pathosis: any deviation from a healthy or normal structure or function; abnormality; illness or malformation.
Some house style guides for medical publications avoid the "illness" sense of pathology (“disease, state of ill health”) and replace it with pathosis. The rationale is that the -ology form should be reserved for the "study of disease" sense and for the medical specialty that provides microscopy and other laboratory services (e.g., cytology, histology) to clinicians. This rationale drives similar usage preferences about etiology ("cause" sense versus "study of causes" sense), methodology ("methods" sense versus "study of methods" sense), and other -ology words.
Not all such natural usage can be purged gracefully, but the goal is to reserve the -ology form to its "study" sense when practical. Not all publications bother with this prescription, because most physicians don't do so in their own speech (and the context makes clear the sense intended).
Another limitation is that pathology (“illness”) has an adjectival form (pathologic), but the corresponding adjectival form of pathosis (pathotic) is idiomatically missing from English (defective declension), so pathologic is obligate for both senses ("diseased" and "related to the study of disease"); this likely helps keep the "illness" sense of pathology in natural use (as the readily retrieved noun counterpart to pathologic in the "diseased" sense).