Asthma is a chronic inflammatory disease of the the lungs and airways that causes difficulty breathing as the airways narrow. Roughly 7,000,000 children are affected by asthma in the United States and it is the most common chronic respiratory disease among children of school age. Asthma can be caused by many different environmental irritants, known as triggers. However, the severity of asthma and its triggers vary widely from individual to individual. Though asthma itself cannot be prevented, you can control certain factors to help reduce the severity and occurrence of symptoms and asthma attacks.