The average length of time for puberty is 2 to 5 years. Puberty tends to begin between the ages of 10 and 15 for boys, and 8 and 13 for girls. These figures represent the average, but it is normal to fall outside of these ranges.
Puberty is the growth stage in which boys' and girls' bodies become sexually mature and capable of reproduction. This process is initiated by the hypothalamus, which sends a signal to the pituitary gland that triggers a release of sex hormones in the ovaries for girls, and the testes for boys.
The main sex hormone produced in boys' testes is testosterone. This stimulates the growth of the penis and testes as well as muscle and body hair. Girls also produce testosterone in small amounts for maintenance of muscle and bone strength. The main hormone produced in girls' ovaries is oestrodiol. This hormone is responsible for the growth of the breasts and reproductive system. Oestrodiol also helps regulate the menstrual cycle. This hormone is found in boys and men as well. It helps to maintain bone density.
Characteristics of puberty vary depending on the individual. Breast development often occurs as a first sign of puberty, but it is normal for body hair to develop first as well. These subjective inconsistencies are the source of insecurity during this stage of life. Boys and girls are advised to discuss these changes with a parent or guardian to mitigate anxiety.