Asthma is a disease that affects the lungs. In the United States, about 20 million people have asthma. Nearly 9 million of them are children. Children have smaller airways than adults, which makes asthma especially serious for them.11 It causes wheezing, breathlessness, chest tightness, and coughing at night or early in the morning. If a person has asthma, they have it all the time, but they will have asthma attacks only when something bothers their lungs. An asthma attack may include coughing, chest tightness, wheezing, and trouble breathing. The attack happens in the body’s airways, which are the paths that carry air to the lungs. As the air moves through the lungs, the airways become smaller, like the branches of a tree are smaller than the tree trunk. During an asthma attack, the sides of the airways in the lungs swell and the airways shrink. Less air gets in and out of the lungs, and mucous that the body makes clogs up the airways.