A little know fact is that hair loss in a percentage number of women occurs for the very same reasons as in men. This site discusses some of them:
Here is a quote from another site ( http://www.webmd.com/skin-problems-and-treatments/hair-loss/understanding-hair-loss-basics)
"Androgenic alopecia is another form of hair loss. It’s a genetically predisposed condition that can affect both men and women. Men with this condition can begin suffering hair loss as early as their teens or early 20s, while most women don’t experience noticeable thinning until their 40s or later.
In men, the condition is also called male pattern baldness. It’s characterized by a receding hairline and gradual disappearance of hair from the crown. In women, androgenic alopecia is referred to as female pattern baldness. Women with the condition experience a general thinning over the entire scalp, with the most extensive hair loss at the crown."
Basically the gene for androgenic baldness responds to male hormones. Post puberty, men have high levels of androgens - testosterone is one of these - but women have androgens too; in fact androgens are a necessary component of the female reproductive hormones.
The androgenic hormone’s effects in premenopausal women are lessened by the much higher levels of estrogen, but are present, and with time do cause thinning. With the onset of menopause, estrogen levels drop and the androgenic effects are increased.
Note: the long term effects of androgens can be seen in the increasing nose/ear/beard/body hair with age in males, as the same hormones cause the scalp follicles on the top of the head to decrease hair production.
Treatments can include several drugs (Rogaine as an example) or wigs, or hair transplant surgery.
Hope this helps.