Asthma is a lung condition that causes wheezing, coughing, and shortness of breath. Asthma is a chronic condition, which means you will probably have it the rest of your life. You may start coughing or wheezing when you breathe in irritants or something you are allergic to. Cold air, viruses, and tobacco smoke are possible irritants. Examples of things you might be allergic to are dust, pollen, molds, and animal dander.
Some people have coughing or wheezing only during or after physical activity.
This is called exercise-induced asthma. Asthma may be mild, moderate, or severe. An asthma attack may last a few minutes or for days. Attacks can happen anywhere and at any time. Severe asthma attacks can be fatal.