This presentation defines epidemiology and the theory of epidemiologic transition proposed by Abdel Omran. It explains that the epidemiologic transition is the process by which patterns of disease and mortality shift from infectious/parasitic diseases to degenerative and man-made diseases as a society develops. The theory outlines five stages: 1) pestilence and famine dominated by infectious diseases, 2) receding pandemics as sanitation and medicine improve, 3) increasing rates of degenerative diseases like heart disease and cancer, and 4) a delayed degenerative stage where life expectancy increases through medical advances but non-communicable diseases rise due to obesity and sedentary lifestyles. The presentation provides details on each stage, highlighting the Black