Hot flashes: epidemiology and physiology.

A review of the literature illustrates the many questions about hot flashes that remain unanswered. My survey addresses some of these questions. The prospective and retrospective descriptions of hot flashes provide a more detailed profile of the hot flash than has previously been available. Further, data from this survey demonstrate that while the patterns of hot flashes may be varied, there are commonalities in hot flash physiology and subjective manifestation. The data indicate that hot flashes may start much earlier and continue far longer than is commonly recognized by physicians or acknowledged in textbooks of gynecology. Studies of hot flash duration must control for age or age at hot flash onset, since the older the subjects, the more potential years of hot flashes and the greater the probability of encompassing the entire period of hot flashes. Hot flashes are not static; patterns may change with time. For some women, hot flashes become less frequent and less intense; for others, hot flashes may continue at hourly intervals well into old age. How common these experiences are for women of all ages still needs to be discovered. As expounded by Kaufert, McKinlay, Goodman, and many others, a greater effort must be made to standardize definitions and question formats as well as to improve methodology in epidemiologic investigations to facilitate comparability between studies and insure that proffered conclusions indeed reflect the questions being asked. Physiological studies are critical counterparts to the epidemiology; yet such studies have been too few. My work, by examining the physiology and psychophysiology of hot flashes, has raised additional questions about central and peripheral inputs that may affect the subjective experience of hot flashes. A more complete understanding of the thermoregulatory, cardiovascular, and psychophysiology of women with hot flashes are compared to women without will facilitate the prediction of who is most likely to be affected and the identification of additional approaches to the management of hot flashes.