National Institutes of Health (.gov)https://www.ncbi.nlm.nih.gov Physiology, Puberty - StatPearls - NCBI Bookshelf
: Usually begins about two years after breast development starts. It is a normal monthly process where the uterine lining is shed if an egg is not fertilized.
Puberty is triggered by hormones from the brain that signal the reproductive organs—the ovaries in females and the testes in males—to begin producing sex hormones. National Institutes of Health (
: Hips widen, and there is an increase in body fat around the stomach and buttocks.
: For girls, the primary hormone is estrogen , while for boys, it is testosterone . : Hips widen, and there is an increase
The first visible sign of puberty in most girls is breast development, often starting as small, tender "breast buds" under the nipple.
: Growth of pubic and underarm hair, a clear or white vaginal discharge, and a rapid growth spurt. Physical Changes in Boys : Growth of pubic and underarm hair, a
The first sign of puberty in boys is usually the enlargement of the testicles.