It is well established that women suffer more asthma symptoms and worse health-related quality of life than men with the same level of asthma severity. The etiology for these sex-related differences in unknown, but a subset of women has premenstrual asthma (PMA) with worsening of their asthma symptoms either prior to or during menstruation. Previous small trials have suggested that an increase in the host inflammatory response may correlate with PMA symptoms. We have evidence that small inhibitory ribonucleic acids, microRNAs, circulating in the peripheral blood of human patients may be expressed in different patterns in certain disease states when compared to healthy individuals.