This word refers to the various disturbances of body functions that underlie disease. We may talk, for example, in neurosurgical practice, of congenitalAn abnormality, structural or otherwise, which is present at birth, although its presence may not become evident until later in life, if at all., infective, traumatic, neoplastic, vascular and degenerative pathologies. These terms encompass, respectively, conditions present at birth, various infections, injuries, growths, stroke and disorders related to ageing.