All women have terminal hair in some parts of the body, specifically the scalp, pubic and axillary area. A few hairs around the nipple or over the thighs may be normal. There is no hirsutism if only the forearms and calves are affected. This last condition is characterized by excessive growth of vellus-type hair, which may be darker than usual. This is very common of women of Mediterranean descent, and usually runs in families.
Hirsutism is almost always the result of excess effect of androgens on the hair follicles.
Most affected individuals are born with various degrees of ambiguous genitalia and present marked hirsutism upon initiation of puberty. These were obese, hirsute and had irregular and infrequent menstrual periods. They attributed the lack of ovulation to the thick capsule. Because until the 1960's there were no drugs to induce ovulation, women with this condition were usually subjected to excision of a wedge of ovary to facilitate ovulation. We know now that the mechanism by which the operation succeeded in promoting ovulation had little to do with the mechanical factors but rather to a change in levels of hormones caused by sudden removal of ovarian tissue.