The classic definition of Health transition or epidemiologic transition is “A characteristic shift in the disease pattern of a population as mortality falls during the demographic transition: acute, infectious diseases are reduced, while chronic, degenerative diseases increase in prominence, causing a gradual shift in the age pattern of mortality from younger to older ages. In general, Epidemiologic transitions (in general), Any major shift in patterns of disease or causes of death that affects the level and character of mortality in a population.