El Khoudary SR, Greendale G, Crawford SL, et al. - In view of the observation that clinical samples of women seeking treatment rather than population-based studies framed the initial understanding of the menopause transition (MT), initiation of the Study of Women's Health Across the Nation (SWAN) was done in 1996 with the aim to describe the MT, to define its biological and psychosocial antecedents and sequelae in an ethnically and racially diverse sample of midlife women. In this review, the central findings of SWAN to date are summarized that can familiarize women and their healthcare providers regarding the influence of the MT and midlife aging on overall health and well-being. In SWAN, description of changes in reproductive axis and menstrual cycle patterns have been made implication of which aided in the development of the reproductive aging staging system Staging of Reproductive Aging Workshop+10. Further, SWAN described MT-related symptoms and mental health (vasomotor symptoms, sleep complaints, psychological symptoms, cognitive performance, and urogenital and sexual health) and influences of MT on physiological systems and functions (cardiovascular and cardiometabolic health, bone health, physical function performance). As per SWAN, there are substantial interrelations among these changes and significant racial/ethnic disparities in the rate and magnitude of variation in multiple health indictors in midlife women. Findings indicate midlife as a crucial stage for adopting healthy behavior and preventive strategies. SWAN may assist in ascertaining if a relation exists between MT-related changes during midlife and unfavorable health and well-being in early old age.