Asthma is a chronic lung disease that is marked by narrowing and inflammation in the airways. The condition causes recurring periods of symptoms that include shortness of breath, wheezing, coughing, and tightness in the chest. It often starts in childhood, but it affects people of all ages and adults can suddenly experience an asthma attack. According to the American Academy of Allergy, Asthma, and Immunology (AAAI), approximately one in 12 people in the United States has asthma – and that number is growing each year.