Editing Menarche (section)

===Puberty===
Menarche is the culmination of a series of [[physiological]] and anatomic processes of [[puberty]]:
* Attainment of a sufficient [[body fat percentage]] (typically around 17% of total body mass).<ref name=hr>{{cite journal | vauthors = Frisch RE | title = Body fat, menarche, fitness and fertility | journal = Human Reproduction | volume = 2 | issue = 6 | pages = 521–33 | date = August 1987 | pmid = 3117838 | doi = 10.1093/oxfordjournals.humrep.a136582 }}</ref>
* Disinhibition of the [[GnRH]] pulse generator in the [[arcuate nucleus]] of the [[hypothalamus]].<ref name="StatPearls">{{cite book | vauthors = Lacroix AE, Gondal H, Langaker MD | chapter = Physiology, Menarche| chapter-url=http://www.ncbi.nlm.nih.gov/books/NBK470216/| title = StatPearls|place=Treasure Island (FL)|publisher=StatPearls Publishing|date=11 March 2023 |pmid=29261991|access-date=11 February 2025}}</ref>
* Secretion of [[estrogen]] by the [[ovary|ovaries]] in response to [[pituitary]] [[hormone]]s.
* Over an interval of about 2 to 3 years, estrogen stimulates growth of the [[uterus]] and [[breasts]], as well as an increase in height, widening of the [[human pelvis|pelvis]], and increased regional [[adipose tissue]].
* Estrogen stimulates growth and vascularity of the [[endometrium]], the lining of the uterus.
* Fluctuations of hormone levels can result in changes of adequacy of blood supply to parts of the endometrium.
* Death of some of the endometrial tissue from these hormone or blood supply fluctuations leads to ''deciduation'', a sloughing off of part of the lining with some blood, which together flows from the [[vagina]], i.e. menstrual flow.

Menarche is not painful and occurs without warning.<ref name="StatPearls" />

The ''menstruum'', or ''flow'', consists of a combination of fresh and clotted blood with endometrial tissue. Menarche is not painful and occurs without warning. Flow may be scanty in amount and might be as little as a single instance of "spotting". Like other [[menstruation|menses]], menarche may be accompanied by lower abdominal cramps.<ref name="StatPearls" />