The project aims to investigate the effect of female sex hormone treatment (both contraceptive treatment and hormone therapy during menopause) on bronchial hyperreactivity in adult women. The study is a prospective cohort study involving 300 women, examining airway responsiveness before and after the initiation of hormone treatment, whether as hormone therapy in menopause or contraceptive treatment. Participants will be recruited from general practitioners in the Capital Region of Denmark. Lung function, bronchial hyperreactivity, airway inflammation, and body composition will be assessed before and after hormone treatment. Blood samples will also be collected and stored for later analysis of inflammation markers. The study will include women aged 18 to 75 who are about to begin hormone treatment.