Abstract
Around 1.2 billion people, or one out of every six persons of the world's population, are adolescents, aged 10 to 19 years. Most of them are presumed to be healthy, but there is still substantial premature death, illness, and injury among adolescents. Illnesses hinder the ability of adolescents to grow and develop to their full potential. Early pregnancy and child birth, unprotected sex, and/or exposure to HIV/AIDS and other sexually transmitted infections can jeopardize not only their current health but also their future health as adults and even the health of their future generations. Promoting healthy behaviors 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 the future health of coming generations as well as their ability to develop and thrive.