It is a period of increased physical growth and a number of physical, hormonal, behavioral, emotional and psychological changes.
During adolescence period, some physical changes are observed such as increase in height, change in voice, change in body shape, development of sex organs, mood swings etc.
An adolescence undergoes mood swings and the behavior changes like self assertiveness and rebellious attitude. There is a feeling of insecurity and a lot of peer pressure and a number of factors like schooling, culture and type of peer group affect these changes.