Why don't female children experience female menopause symptoms?

If the cause of the symptoms are low estrogen, why don’t prepubescent female children experience them?
Estrogen levels are low before puberty.
In adult women, low estrogen causes heat-sweats, hairloss, brittle bones, diabetes and other nasty stuff.

So why exactly do these symptoms only appear in adults with low estrogen? Is it withdrawal?

For that matter why don’t male children/adults have those symptoms?

Note also that post-menopausal women don’t have those symptoms, either. It’s not the hormone levels themselves; it’s the change in the hormone levels (in fact, “the change” is a common euphemism for menopause). A prepubescent child, a woman in the prime of her life, or an elderly woman all have relatively stable hormone levels (well, the woman in her prime has monthly variations, and those can also cause side effects). But a person in transition between those stages, in menopause or puberty, has changing hormone levels, which cause problems (different problems, because they’re different changes).

Post-menopausal women may not have have some of those symptoms - but bones don’t stop getting brittle and the hair doesn’t get thicker once a woman has completed menopause. Hot flashes can continue for years after the last period and genitourinary symptoms are apparently more common post-menopause than during. So it can’t just be a matter of unstable hormone levels.

The flushing in menopausal women isn’t so much caused by the low estrogen as it is the body’s and the brain’s (hypothalamus) response to dropping estrogen levels. This is reviewed here but is a complex business.

When estrogen levels drop in a post-pubertal woman, her hypothalamus tries to re-stimulate estrogen production by secreting various proteins (peptides). It is the release of these and other neuropeptides, either directly or indirectly, that leads to flushing since in addition to stimulating estrogen release, they also affect the sensitivity or ‘gain’ in the body’s temperature regulation system, and that makes for unpredictable episodes where the blood vessels dilate to give off heat.

It helps to remember that many ‘vegetative’ processes in the body, such as body temperature regulation, appetite, puberty, thirst, emotion, etc. are controlled by the hypothalamus, so spillover effects may not be completely unexpected when there are surges in neuropeptide production.

Your question is a very interesting one but the real mystery is what controls (the onset of) puberty and how passing through puberty resets the hypothalamus.

Well, there’s also the fact that getting old causes changes that aren’t necessarily linked to sex hormones–or maybe they are, because men go through the andropause too, when their testosterone levels drop and they see physical and emotional changes related to that as well.

It makes nearly as much sense to think of the sexually active years as being the anomaly, the time when the hormone levels go way out of whack to facilitate childbearing. In an average lifespan we spend about half the time with the “normal” baseline hormone levels and half the time at the elevated levels with all the associated weird issues those bring. I’m not sure it’s correct to think of the elevated time as being the normal one with the lower hormone times being the outlier.

As a recently menopausal, woman, I’ve been wondering about this, too.

But children have relatively high levels of growth hormone, don’t they? I would guess that this and perhaps other metabolic differences between children and adults affects bone density and hair growth. And men have testosterone, which I think has similar beneficial effects on bones and hair (except when too much of it kills follicles, as in “male-pattern baldness”).