Adolescence is a period of biological, psychological, sexual and social development that typically occurs between ages 10-12 and 19-20. During this time, both males and females experience physical changes like growth of sexual organs and pubic hair. Some other physical changes seen in adolescence include increases in weight, body fat, head size, and muscle growth. Psychologically, adolescents may feel more moody, aggressive, rebellious, isolated or unstable. They also start experiencing romantic attraction to others. Some risks during adolescence include issues with pubertal development, family problems, eating disorders, intellectual risks, biological factors, sexual risks, and social factors.