Overview
How the Syndrome Creates Its Clinical Pattern
Polycystic ovary syndrome is an endocrine metabolic syndrome involving androgen excess, disordered ovulation, and, in some patients, polycystic ovarian morphology.
Polycystic ovary syndrome is an endocrine-metabolic syndrome involving androgen excess, disordered ovulation, and, in some patients, polycystic ovarian morphology. These features often occur together, but a patient does not need all three to meet diagnostic criteria. Insulin resistance can intensify the syndrome. Compensatory hyperinsulinaemia stimulates ovarian androgen production and reduces sex hormone-binding globulin, leaving more circulating androgen biologically active. Follicles then begin developing but fail to mature and ovulate consistently. The result is infrequent or absent menstruation, infertility related to anovulation, hirsutism, acne, or androgen-pattern scalp hair loss. Insulin resistance is common but not universal. A patient with a normal body mass index can still have PCOS and metabolic risk; excess weight may worsen the condition but is not required for diagnosis. Acanthosis nigricans—dark, thickened, velvety skin in the neck, axillae, or other folds—supports insulin resistance but is not itself a diagnostic criterion. Chronic anovulation also affects the endometrium. Without regular progesterone exposure after ovulation, the endometrium may remain under oestrogenic stimulation for prolonged periods. This increases the risk of endometrial hyperplasia and makes prolonged amenorrhoea or atypical bleeding clinically...