Dating girl psoriasis
Nutritional and other environmental influences may be responsible for this change.For example, the average age of the onset of menstrual periods in girls was 15 in 1900.
"Secondary sex changes" are those physical changes associated with the progressive rise in sex hormones -- estrogen and progesterone in females and testosterone in males.
The changes that happen during the process of puberty have a typical pattern in both boys and girls, with a generally predictable sequence of events.
In most girls, the first sign of puberty is the beginning of breast development (breast buds), which occurs at an average age of approximately 11 years.
Such secondary sex changes include The timing of the onset of puberty is not completely understood and is likely determined by a number of factors.
One theory proposes that reaching a critical weight or body composition may play a role in the onset of puberty.