Asthma is a lung condition that causes wheezing, coughing and shortness of breath. It is caused by inflammation (swelling) of the lining of the airways in your lungs. Asthma is a chronic condition, which means you may have it for the rest of your life.
You may start coughing or wheezing when you breathe in irritants or something you are allergic to. Cold air, chemicals, perfume and smoke are examples of irritants. Examples of things you might be allergic to, called allergens, are dust, pollen, molds and animal dander. A viral respiratory infection might also bring on an asthma attack.
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. It is very important to get prompt treatment for asthma attacks and to learn to manage your asthma so you can live a healthy, active life.v
About 12 million Americans have asthma, and the number of people who have asthma is increasing worldwide.