Adolescent health, or youth health, is the range of approaches to preventing, detecting or treating young people's health and well-being. The term adolescent and young people are often used interchangeably, as are the terms Adolescent Health and Youth Health. Young people's health is often complex and requires a comprehensive, biopsychosocial approach. Because adolescence represents a life stage of increasing psychosocial independence, but one of limited legal and social rights (for those who have not reached the legal age of adulthood where they reside), adolescent health exists at the intersection of many forces often outside of the control of individual young people. Some young people might have a history of adverse childhood experiences (ACEs), or may be actively living in or experiencing the situations described as ACEs. The Adverse Childhood Experiences Study suggests that ACEs are common, and are predictive of adverse physical health outcomes (ischemic heart disease, cancer, chronic lung disease) in adults. Social, cultural and environmental factors are all important areas of focus in adolescent health. Young people have specific health problems and developmental needs that differ from those of children or adults: The causes of ill-health in adolescents are mostly psychosocial rather than biological. Young people often engage in health risk behaviours that reflect the processes of adolescent development: experimentation and exploration, including using drugs and alcohol, sexual behaviour, and other risk taking that affect their physical and mental health. Adolescent health also encompasses children's and young people's sexual and reproductive health (SRH). The World Health Organization describes the leading health-related problems in the age group 10 – 19 years to include: Early pregnancy and childbirth HIV Other infectious diseases Mental health problems including depression and suicide Violence Alcohol and other drugs Injuries both unintentional and self-injury Sexual health / Infectious diseases Malnutrition and obesity Exercise and Nutrition Tobacco use Rights of adolescents Adolescent and young adult oncology Young people often lack awareness of the risks of harm associated with certain behaviours, or may overestimate the risks of some behaviours while underestimating the risks of others.