Adrenal hyperandrogenism is a common feature of polycystic ovary syndrome (PCO). It is controversial whether the noncongenital adrenal hyperplasia disorders represent some sort of primary defect within the adrenal gland or are secondary to the effects of the abnormal hormonal milieu on adrenal enzyme activity, either the high androgen or luteinizing hormone levels. Adrenal androgens, both directly and by their aromatization to oestrogens, can cause the clinical and biochemical syndrome of PCO.