Please note that the mortality and morbidity estimates have been updated using the Global Health Estimates for the year 2021, published in 2025, and are therefore not in line with the estimates published in the PDF version of the AA-HA! 2.0. Similarly, the risk factor estimates have been updated using the Global Burden of Disease Estimates for the year 2021.
Approximately 1.3 billion (16%) of the global population are adolescents, between the ages of 10 and 19 years.
Over the last 20 years, mortality rates from all causes have declined among adolescents globally, with the largest decline in older (15–19 years) adolescent girls. However, progress has been uneven across different regions and adolescent population groups.
Globally, road injury was the most important cause of death for both younger (10–14-year-old) and older (15–19-year-old) adolescent males in 2021. Among adolescent females, the most important causes of death were lower respiratory infections in the younger group and maternal conditions in the older group.
Reductions in the burden of non-fatal diseases among adolescents have been limited over the past 20 years. In fact, there have been increases in some regions and age groups. Across regions, the main conditions causing this burden in 2021 were mental health conditions (depressive and anxiety disorders, childhood behavioural disorders), iron deficiency anaemia, skin diseases, migraine, and back and neck pain. Conditions such as malaria or drug use disorders were more common in certain regions.
Globally, in 2021 across adolescent sex and age groups, the most important risk factors for mortality and morbidity included iron deficiency, unsafe water source and unsafe sanitation, low birthweight, short gestation. Among the older adolescent age groups, occupational injuries, high alcohol use, bullying victimization and unsafe sex were also important risks.
Evidence is growing of the role of protective factors at individual, family and societal levels on adolescents’ health and well-being.
This chapter describes the situation of adolescent health and well-being. Section 2.1 presents an overview of the adolescent mortality and morbidity burden and risk factors for adolescent health and well-being. Section 2.2 presents an overview of protective factors for adolescent health and well-being. Section 2.3 then gives more details about selected outcomes and determinants for adolescent health and well-being. Finally, section 2.4 details the particular nature of adolescent health burdens in humanitarian and fragile settings.
What is new in this chapter?
Updated data on the adolescent population, their mortality, morbidity, selected health outcomes, and risk and protective factors, as well as determinants of their health and well-being
The mortality and morbidity burden among adolescents, and the main causes, now presented separately rather than combined in disability-adjusted life years (DALYs). The morbidity burden is expressed as years of healthy life lost due to disability (YLDs) and captures morbidity as the amount of time lived in states of less than good health. For example, a YLD rate of 544 per 100 000 adolescent population for a specific condition means that, among 100 000 adolescents in a given year, 544 years of healthy life have been lost due to poor health related to this condition.
An overview of protective factors for adolescent health and well-being.
