Exacerbation of asthmatic symptoms just before or at the time of menstruation documented in some women with asthma has been called "premenstrual asthma" (PMA). The effect of sex hormones on airway function has not been well studied in spite of much evidence to suggest, therefore about relationships between the sex hormones and airway. The investigations of (PMA) have been based on studies of asthmatics already aware of a deterioration of asthma premenstrually. Little is known, therefore, about relationships between the menstrual cycle with asthma and (PMA) subjects. Although the mechanism of PMA remains unclear.