In high-income countries, 7 in every 10 deaths are among people aged 70 years and older. People predominantly die of chronic diseases: cardiovascular diseases, cancers, dementia, chronic obstructive lung disease or diabetes. Lower respiratory infections remain the only leading infectious cause of death. Only 1 in every 100 deaths is among children under 15 years.
In middle-income countries, chronic diseases are the major killers, just as they are in high-income countries. Unlike in high-income countries, however, diarrhoeal diseases, road injury, HIV/AIDS and prematurity also are leading causes of death.
In low-income countries, nearly 4 in every 10 deaths are among children under 15 years, and only 2 in every 10 deaths are among people aged 70 years and older. People predominantly die of infectious diseases: lower respiratory infections, HIV/AIDS, diarrhoeal diseases, malaria and tuberculosis collectively account for almost one third of all deaths in these countries. Complications of childbirth due to prematurity, and birth asphyxia and birth trauma are among the leading causes of death among children under 5 years old, claiming the lives of many newborns and infants.