Young boys and girls experience the development of secondary sex characteristics differently.
Most girls experience breast development followed by pubic and arm hair growth. Growth spurts, increase in hip size, and vaginal secretions are also common. The first menstrual period takes place approximately two years into puberty.
Young boys first experience enlargement of the testicles followed by growth spurts, penis growth, increased hair growth, voice changes, and wet dreams.
In addition to physical changes, adolescents also experience cognitive, social, and emotional development.