Global health is the health of the populations in the worldwide context; it has been defined as "the area of study, research, and practice that places a priority on improving health and achieving equity in health for all people worldwide". Problems that transcend national borders or have a global political and economic impact are often emphasized. Thus, global health is about worldwide health improvement, reduction of disparities, and protection against global threats that disregard national borders, including the most common causes of human death and years of life lost from a global perspective.
The World Health Organization in Geneva, Switzerland
Open Global Health at OpenCon 2015
Global number of deaths (A) and YLLs (B), by pathogen and GBD super-region, 2019
Overall age-standardised mortality rate per 100 000 population for 33 pathogens investigated, 2019
Health has a variety of definitions, which have been used for different purposes over time. Health can be promoted by encouraging healthful activities, such as regular physical exercise and adequate sleep, and by reducing or avoiding unhealthful activities or situations, such as smoking or excessive stress. Some factors affecting health are due to individual choices, such as whether to engage in a high-risk behavior, while others are due to structural causes, such as whether the society is arranged in a way that makes it easier or harder for people to get necessary healthcare services. Still, other factors are beyond both individual and group choices, such as genetic disorders.
Donald Henderson as part of the CDC's smallpox eradication team in 1966
Modern drug ampoules
Nurses in Kokopo, East New Britain, Papua New Guinea
Postage stamp, New Zealand, 1933. Public health has been promoted – and depicted – in a wide variety of ways.