<P> The pathogenesis of a disease is the biological mechanism (or mechanisms) that leads to the diseased state . The term can also describe the origin and development of the disease, and whether it is acute, chronic, or recurrent . The word comes from the Greek πάθος pathos ("disease") and γένεσις genesis ("creation"). </P> <P> Types of pathogenesis include microbial infection, inflammation, malignancy and tissue breakdown . For example, bacterial pathogenesis is the mechanism by which bacteria cause infectious illness . </P>

The medical term pathogenesis is best defined as