Puberty is the period, after childhood, between 9 and 20 years old approximately. At this stage psychological, biological, sexual and social changes, which can lead to certain diseases occur. Among the best-known disorders highlights puberty delayed puberty, in which a boy or a girl, arrived 14 years, it has not yet started the physical and psychological development into adolescence. This late development may be due to genetic factors, hormonal causes, chromosomal abnormalities or tumors that affect hormone secretion glands or hypothalamus. Instead, another disorder associated called early puberty is the beginning of physical changes in children prematurely (before age 12): in girls is often caused development of breast button below seven years and pubic hair before eight; and children is the appearance of pubic hair and genitals elongation between 7 and 10 years. Both early and late puberty can occur only partially or completely.