Child mortality, also known as under-5 mortality, refers to the death of infants and children under the age of five. In 2010, 7.6 million children under five died , down from 8.1 million in 2009, 8.8 million in 2008, and 12.4 million in 1990. About half of child deaths occur in Africa. Approximately 60 countries make up 94% of under five child deaths. Reduction of child mortality is the fourth of the United Nations' Millennium Development Goals.

According to UNICEF, most child deaths (and 70% in developing countries) result from one the following five causes or a combination thereof:

Two-thirds of deaths are preventable. Malnutrition and the lack of safe water and sanitation contribute to half of all these children’s deaths. Research and experience show that most of the children who die each year could be saved by low-tech, evidence-based, cost-effective measures such as vaccines, antibiotics, micronutrient supplementation, insecticide-treated bed nets, improved family care and breastfeeding practices , and oral rehydration therapy. In addition to providing vaccines and antibiotics to children, education could also be provided to mothers about how they can make simple changes to living conditions such as improving hygiene in order to increase the health of their children. Mothers who are educated will also have increased confidence in the ability to take care of their children, therefore providing a healthier relationship and environment for them.

Hans Rosling (born 27 July 1948 in Uppsala, Sweden) is a Swedish medical doctor, academic, statistician and public speaker. He is Professor of International Health at Karolinska Institute and co-founder and chairman of the Gapminder Foundation, which developed the Trendalyzer software system.

From 1967 to 1974 Rosling studied statistics and medicine at Uppsala University, and in 1972 he studied public health at St. John's Medical College, Bangalore. He became a licenced physician in 1976 and from 1979 to 1981 he served as District Medical Officer in Nacala in northern Mozambique.

On 21 August 1981, Rosling discovered an outbreak of konzo, a paralytic disease, and the investigations that followed earned him a Ph.D. degree at Uppsala University in 1986. He spent two decades studying outbreaks of this disease in remote rural areas across Africa and supervised more than ten Ph.D. students^{[citation needed]}. Outbreaks occur among hunger-stricken rural populations in Africa where a diet dominated by insufficiently processed cassava results in simultaneous malnutrition and high dietary cyanide intake.