Asthma is a serious and ongoing disease that affects the airways of both adults and children. Airways are the tubes that carry air in and out of the lungs. Asthma is a chronic, long-term disease with no cure. But there are ways to help prevent asthma symptoms from occurring in the first place. More than 20 million people in the United States have asthma. And every day, about 60,000 of them miss school or work; 5,000 visit the emergency room; and more than 1,000 are admitted to the hospital. All because asthma symptoms aren't prevented as they could be