MethaCholine Bronchoprovocation Study (MeCIS)

The purpose of this research is to evaluate the methacholine challenge test as an accurate indicator of asthma in patients receiving treatment for asthma. Phase 1 on the study compares methacholine challenge test results from asthma patients to those from people who do not have asthma. In phase 2, test results for people with asthma on low dose inhaled corticosteroid will be compared to results on high dose inhaled corticosteroids. Both males and females with stable asthma (asthma participants) and without asthma (controls) enrolled. Participants will be between 12 and 69 years of age.