23. Aging and the female hypothalamus

Throughout medical history, humans have sought to understand the menopause. But, until about 1900, most women died before they ever experienced this "change of life," so it never presented the challenge to clinicians, basic scientists, and social and behavioral scientists it presents today. During this century, the average lifespan of humans has increased dramatically. Today, in the United States, the average lifespan for women is 83 years. There are over 35 million women who are postmenopausal; more than 1 million will join these ranks each year. Thus, an increasing number and an increasing proportion of women will live a larger fraction of their lives in the postmenopausal state than ever before. Obviously, it becomes critical to gather reliable, extensive and in-depth information about the biological, medical, societal and economic implications of the transition women make from a reproductive to nonreproductive status. This chapter concentrates on the biomedical causes of the menopausal transition.