Asthma is the condition in which a person experiences difficulty breathing due to their airways swelling up and narrowing. They may produce excess mucus, as well as develop a heavy cough. Exposure to triggers can make an asthmatic person develop symptoms such as shortness of breath, tightness in the chest, and heavy mucus, which can lead to fatigue and respiratory dysfunction. In severe cases, asthma can be life threatening. As of yet, asthma is incurable, although symptoms can be controlled.