This completely updated chart defines asthma and discusses possible causes. Illustrates and describes what happens during as asthma attack and contrasts an affected bronchiole with a healthy bronchiole. Shows and describes how the lungs work. Provides a chart "Monitoring Your Asthma by Zone" which matches various degrees of asthma symptoms with appropriate actions. Symptoms for adults and children are listed. Also provides common triggers and information on monitoring and managing asthma.