Mechanisms Underlying the Definition of asthma Risk Factors (for development of asthma) INFLAMWATJON Airway Hyperresponsiveness Airflow obstruction Risk Factors Symptoms (for exacerbations)Mechanisms Underlying the Definition of Asthma Risk Factors (for development of asthma) INFLAMMATION Airway Hyperresponsiveness Airflow Obstruction Risk Factors (for exacerbations) Symptoms