Epidemiology
Epidemiologists aim to understand the causes of health problems by looking at the relationship between agents, hosts, and environmental factors that affects health. Using these information, they also design public health interventions to solve various health problems among populations. They regularly evaluate the health of populations, tries to identify which populations have greater risk from specific causes of diseases, and evaluates the effectiveness of the intervention programs or methods that they create. In essence, epidemiology provides the foundation of public health and preventative medicine practices.