Hair loss can be just as common among women as men, but it is not as noticeable, since it happens to men and women in very different ways. Men lose a bigger volume of hair due to androgenic alopecia, or male pattern baldness. Where men have obvious bald spots, women lose hair more subtly and often just have hair that feels and looks a little thinner all over.
The female pattern for hair loss is around the top of the entire head, while for men, hair loss occurs in the crown, temple, and "bald spot" areas of the scalp. The different receptor sites of enzymes and hormones account for the pattern differences between men and women. Some women have a genetic predisposition to hair loss as a large amount of testosterone in their systems reacts with hair cell enzymes to produce thinning hair.
All humans daily shed and regrow hair. Alopecia, or baldness, results when the normal human pattern of hair growth is out of balance. The normal pattern of hair growth is growing, resting, and shedding and if the hair growth pattern is out of balance, hair does not regrow as fast as it sheds. Whites are more prone to male pattern baldness than the Japanese. Blacks are likely to experience more hair loss than whites.
Many women do not realize their hair loss until they feel their thinning hair when putting their hair into a ponytail or braid. The differences in men's and women's hairstyles can also make men's balding more noticeable. Sometimes over-processing hair can cause hair thinning, such as bleaching, coloring, or using strong shampoos. Hormones during aging and menopause may cause a women's hair to become thinner. High amounts of vitamin A and medications such as Allopurinol/Zyloprim and Coumadin/Warfarin may also affect hair.
Other causes of hair loss include anemia, severe dieting, surgery, and emotional trauma. Polycystic ovary syndrome, childbirth, and thyroid disorders can also be causes of female pattern baldness. Some autoimmune diseases can cause hair to fall out in clumps, which is called alopecia areata. Hair loss may sometimes be the only symptom of a disease, so women should visit a specialist in female pattern baldness to be checked for possible underlying medical causes.