The term pathogenesis means step by step development of a disease and the chain of events leading to that disease due to a series of changes in the structure and /or function of a cell/tissue/organ being caused by a microbial, chemical or physical agent. The pathogenesis of a disease's the mechanism by which an etiological factor causes the disease. The term can also be used to describe the development of the disease, such as acute, chronic and recurrent. The word comes from the Greek pathos, "d… (More on Pathogenesis)