Public Health has gone through a difficult historical journey to reach its current state in terms of both a scientific discipline and services. With the development of research methods in the 19th century, cause-effect relationships in the emergence of health problems began to be better defined. A better understanding of the relationship between working conditions and diseases led to the development of the occupational health discipline, and similarly, the scientific foundations of environmental health and nutrition disciplines were laid. With the development and mass administration of vaccines, which can be described as the golden invention of public health, disabilities and deaths caused by many infectious diseases, especially smallpox and polio, could be prevented.

Life expectancy at birth and healthy life expectancy have increased significantly in the last century all over the world, especially in high-income countries; the most common causes of illness and death began to change; the impact of health behaviors was beginning to be better understood. It shows that all social determinants, especially people’s education, profession, income, and the conditions of the environment in which they live and work, may be more important than health services or lifestyle choices in the formation of health behaviors. The Global Commission on Social Determinants of Health, which continues its work within the World Health Organization (WHO), emphasizes that only equitable access to health services is not enough, but also that it is necessary to work with sectors outside the health system to ensure broader social welfare and development. In this regard, WHO draws attention to the importance of the “Health in All Policies” approach.