WHO headquarters in Geneva, Switzerland

Photo courtesy WHO; Photo by P.Virot

The World Health Organization, or WHO, was established as a specialized agency of the United Nations (UN) in 1948. It was declared officially in existence on April 7 of that year, after more than half of the UN members signed its constitution. That date is now celebrated as World Health Day.

The objective of WHO is ambitious, stated as "the attainment by all peoples of the highest possible level of health," with health being very broadly defined as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity." WHO works to reach this lofty goal by directing and coordinating international health work.

WHO has been instrumental in eradicating smallpox, once among the most feared diseases, and has helped contain old diseases such as cholera and typhoid and relatively new ones such as SARS and HIV. WHO has led efforts in health-related fields like sanitation, injury prevention, and public health, and is currently working to combat tobacco use and chronic diseases like cancer and diabetes.

In this article, we'll examine how WHO functions and look at its impact on people's health around the world.