Female pattern baldness is due to a combination of a family history of balding (in men or women from either parent's side of the family), aging, and hormones. Female pattern baldness is not due to a vitamin deficiency, poor circulation, dandruff, or wearing hats. There is progressive shrinking of the hair follicles until they produce only a fine, wispy hair or cease functioning.
Hair loss can have a significant psychologic impact, particularly in western society, which puts such a large emphasis on appearance.
For mild to moderate hair thinning, creative hair styling, hair weaving, or hairpieces may be adequate to improve appearance. Protect the scalp from sunburn with a hat.
The only medication approved to treat women in the US is topical minoxidil; the 2% preparation recommended for women is available over the counter. This may help hair to grow in a quarter of the women using it, and it will stop or slow hair loss in the majority of users. The medication is expensive, however, and the hair will fall out when its use is discontinued.
There is no known prevention for hair loss; shampooing and other hair products have no adverse effects other than harsh products or practices that may damage the hair shaft, causing breakage.
If you have hair loss that is cosmetically concerning and other causes have been ruled out, you might consult a surgical specialist in hair replacement.
Current therapies are aimed at stimulating regrowth of terminal hairs and might include topical minoxidil, and the oral medications spironolactone or cyproterone acetate (not available in the US). Finasteride, also an oral medication, is approved for male balding only, and studies show no effect for female pattern hair loss.
Finasteride, spironolactone, and cyproterone should not be used in women of childbearing potential.
Surgical therapy to improve the appearance includes scalp reduction, flaps, and hair transplants (micrografting). Not everyone is a good candidate for these procedures.