As with many other specialties, sleep medicine has been shifting toward helping clinicians obtain a better understanding of gender-specific issues in disorders and disturbances. It is easier today to appreciate the complex dynamics of biological, psychosocial, and cultural factors that define sleep patterns and problems in women. Sleep in women changes across their life spans, with three major shifts likely due to hormonal differences: at the onset of the menstrual cycle, during pregnancy, and during the perimenopausal period