Asthma is a chronic disease that is characterized by both inflammation and a heightened senstivity of the airways to certain triggers. It affects both children and adults. In asthma, the inflammation of the airways causes them to swell and fill with mucous. In turn, the airways become more sensitive and the muscles around the airways tighten. This restricts airflow into the lungs and creates the symptoms of asthma. Asthma symptoms can include: coughing, wheezing, chest tightness, and shortness of breath.