Around 1.2 billion people, or 1 in 6 of the world's population, are adolescents aged 10 to 19. Most are healthy, but there is still substantial premature death, illness, and injury among adolescents.

Promoting healthy behaviours during adolescence, and taking steps to better protect young people from health risks are critical for the prevention of health problems in adulthood, and for countries' future health and ability to develop and thrive.

The main health issues include:

Early pregnancy and childbirth

The leading cause of death for 15– 19 year old girls globally is complications from pregnancy and childbirth. Better access to contraceptive information and services can reduce the number of girls becoming pregnant and giving birth at too young an age. Laws that specify a minimum age of marriage can help.

HIV

More than 2 million adolescents are living with HIV. Although the overall number of HIV-related deaths is down 30% since the peak in 2006 estimates suggest that HIV deaths among adolescents are rising. Better access to HIV testing and counselling, and stronger subsequent links to HIV treatment services for those who test HIV positive, are also needed.

Mental health

Depression is the third leading cause of illness and disability among adolescents, and suicide is the third leading cause of death in older adolescents (15–19 years). Violence, poverty, humiliation and feeling devalued can increase the risk of developing mental health problems. Building life skills in children and adolescents and providing them with psychosocial support in schools and other community settings can help promote good mental health.

Violence

Violence is a leading cause of death in older adolescent males. Globally, 1 in 10 girls under the age of 20 years report experiencing sexual violence. Promoting nurturing relationships between parents and children early in life, providing training in life skills, and reducing access to alcohol and firearms can help to prevent injuries and deaths due to violence.

Alcohol and drugs

Harmful drinking among adolescents is a major concern in many countries. It reduces self-control and increases risky behaviours, such as unsafe sex or dangerous driving. Setting a minimum age for buying and consuming alcohol and regulating how alcoholic drinks are targeted at the younger market are among the strategies for reducing harmful drinking.

Drug use among 15–19 year olds is also an important global concern. Drug control may focus on reducing drug demand, drug supply, or both, and successful programmes usually include structural, community, and individual-level interventions.

Injuries

Unintentional injuries are the leading cause of death and disability among adolescents. In 2015, over 115,000 adolescents died as a result of road traffic accidents. Young drivers need advice on driving safely, while laws that prohibit driving under the influence of alcohol and drugs need to be strictly enforced.

Exercise and nutrition

Iron deficiency anaemia is the leading cause of years lost to death and disability in 2015. Iron and folic acid supplements are a solution that also helps to promote health before adolescents become parents. Regular deworming in areas where intestinal helminths such as hookworm are common is recommended to prevent micronutrient (including iron) deficiencies.

Developing healthy eating and exercise habits in adolescence are foundations for good health in adulthood.

Tobacco use

The vast majority of people using tobacco today began doing so when they were adolescents. Prohibiting the sale of tobacco products to minors and increasing the price of tobacco products through higher taxes, banning tobacco advertising and ensuring smoke-free environments are crucial.