Adolescence is a period characterized by rapid physical, cognitive and social changes, including sexual and reproductive maturation; the gradual building up of the capacity to assume adult behaviours and roles involving new responsibilities requiring new knowledge and skills.

While adolescents are in general a healthy population group, adolescence also poses new challenges to health and development owing to their relative vulnerability and pressure from society, including peers, to adopt risky health behaviour. These challenges include developing an individual identity and dealing with one’s sexuality. The dynamic transition period to adulthood is also generally a period of positive changes, prompted by the significant capacity of adolescents to learn rapidly, to experience new and diverse situations, to develop and use critical thinking, to familiarize themselves with freedom, to be creative and to socialize.