Asthma is a common pulmonary condition defined by chronic inflammation of respiratory tubes, tightening of respiratory smooth muscle, and episodes of broncho-constriction. The Centers for Disease Control and Prevention estimate that 1 in 11 children and 1 in 12 adults have asthma in the United States of America. According to the World Health Organization, asthma affects 235 million people worldwide. There are two major categories of asthma: allergic and non-allergic. In both cases, bronchoconstriction is prominent.