Allergic asthma is usually diagnosed by the presence of variable airway obstruction, bronchial hyperresponsiveness, and allergy. However, a significant proportion of adult asthma patients (up to 40%) are non-allergic. Patients with non-allergic asthma often have a later disease onset and greater disease severity, as reflected by more severe airway obstruction and bronchial hyperresponsiveness. Furthermore, females have a higher risk of developing non-allergic asthma. The latter suggests that hormone-related events play an important role in the development and severity of adult-onset non-allergic asthma. This paper describes the associations between asthma and hormonal changes throughout the female life-span, such as those associated with the monthly cycle of menstruation and menopausal hormonal changes.