What is asthma? Asthma is a chronic lung disease marked by acute flare-ups of inflammation and swelling of the airways in the lungs. Asthma is one of the most common childhood diseases, but it also affects adults. According to the Centers for Disease Control and Prevention, more than 17 million adults and 7 million children are living with asthma in the United States. Seventy five percent of new asthma cases are diagnosed before the 7th birthday. Asthma affects the bronchioles, small hollow passageways in the lungs, and the alveoli, which are attached to the bronchioles. The alveoli are tiny sac-like structures where oxygen is absorbed into the bloodstream. During an asthma attack, the bronchioles and alveoli overreact to certain triggers and become inflamed, irritated, and swollen. This hinders the flow of air into the lungs and causes wheezing, chest tightness, difficulty breathing, and coughing. The smooth muscles surrounding the airways react by tightening, further blocking airflow. Mucus production increases, further exacerbating breathing troubles. Minor shortness of breath can be treated at home by following your treatment plan or at a doctor’s office. If you have trouble breathing, with or without chest tightness or wheezing, after taking your medications according to your treatment plan, contact your health professional. More severe asthma attacks can quickly progress from minor shortness of breath to a life-threatening situation. Get immediate help (call 911) for symptoms such as sweating and severe difficulty breathing, which may be combined with pale or blue lips, fast heart rate, and anxiety.