It is an endocrine condition, affecting many hormones throughout a woman's body, and impacting multiple organ systems and metabolic processes. It manifests itself in a diverse set of symptoms that are seemingly unrelated. Yet all of the symptoms are very much a part of the same condition.
Poly-Cystic Ovary Syndrome – PCOS – is the most common endocrine disease that affects women of reproductive age (puberty to menopause). It is also one of the most confusing. It affects approximately 10% of women in the reproductive age group. There have been some new developments that are giving us a much better understanding of this problem.
PCOS is an unfortunate term because the word “ovarian” appears in the name of this syndrome. For years, many people automatically assumed that it is purely an ovarian disease. We now recognize that it is in fact, a systemic endocrine and metabolic disorder. Multiple factors are at work. It should really be called the “Poly-Cystic Ovary/Excess Androgen Production /Adrenal Hyperplasia / Insulin Resistant / Hyperpipidemic / Often Overweight / Anovulatory /Hirsute / Sometimes Acne” Syndrome.
PCOS is a total body endocrine disease. It is unfortunate and confusing that the word “Ovary” appears in the name. The abnormalities in the ovary are really more the result of the problem – not the cause.
The problem is further complicated by the fact that there is really no universal definition of PCOS even though most endocrinologists would agree on a set of criteria necessary to make the diagnosis. If there is one absolute that is necessary to make the diagnosis of PCOS, it is the complete or almost complete lack of ovulation. Women who are ovulating regularly on their own, cannot, by definition, have PCOS. There are however Reproductive Endocrinologists who feel that women who have all the features of PCOS except for the fact that they ovulate may have a subset of the syndrome. However, these women are much less likely to be insulin resistant.
The other criteria that must be satisfied is that the women have either clinical or laboratory evidence of increased androgen (male hormone) production, either facial hair and/or acne. Source
It is characterized as a "twin sister" to diabetes.
Here are some helpful 'medical' links...