The Seattle Midlife Women's Health Study (SMWHS) is a longitudinal study funded by the National Institutes of Health, National Institute of Nursing Research. The aim of the current five year (2001-2006) study is to describe the changes that occur in midlife women in their menstrual cycles and in their lives as they progress through the menopausal transition and into the postmenopausal phase of life.

Of particular interest are changes in symptoms (measured in a quarterly three day diary), ovarian and adrenal hormones (measured by quarterly urine specimens), menstrual cycle changes (measured with a menstrual calendar and a yearly questionnaire), stress (measured in the diary, the urine specimens and in the questionnaire), and use of health services and hormone use (both measured with the yearly questionnaire).