In 1983, when the Healthy Women Study began, there was a paucity of epidemiological studies of cardiovascular risk factor changes and risk of heart disease related to natural menopause. The Healthy Women Study was one of the few in which the status of premenopausal women was followed carefully through and subsequent to the menopause. The study also included detailed behavioral and biological measures, as well as important environmental factors related to the determinants of these risk factors.