Increasing attention is currently being directed to a variety of health disorders that are either unique to or more common among women than men. This volume adds sleep disorders to the list of those in which important gender differences have been neglected. Sleep Disorders in Women: A Guide to Practical Management - plores the reasons for gender bias in this area of research and provides a comp- hensive and in-depth review of what is currently known and what still remains to be studied concerning this important topic. As several contributors to this volume indicate, numerous misconceptions exist due, not surprisingly, to a shortage of reliable data in the field. As an example, obstructive sleep apnea (OSA) is typically thought to be far more common in men than in women. However, as contributors to this volume carefully document, the prevalence of OSA in women varies considerably depending on the specific female population that is studied. It is low in premenopausal women, higher in postme- pausal women, particularly high in women with polycystic ovary syndrome, and of uncertain prevalence in pregnancy. This exemplifies the fact that as women move through varying hormonal environments including puberty, the menstrual cycle, use of oral contraceptives, pregnancy, the postpartum period, and menopause, their risk for a variety of sleep disorders varies considerably. As pointed out in Dr.