Asthma-What Is It?
Asthma is a chronic lung diseases that causes breathing difficulties and wheezing when air passages narrow and become inflamed. The situation ranges from mild to severe. Some people have only intermittent, mild symptoms, while others have almost constant symptoms with severe, life-threatening flare-ups.
During an asthma attack, the airways become inflamed and narrower as the muscles surrounding them constrict. The flow of air is blocked partially or completely as mucus produced by the inflammation fills a narrower passageway. Asthma affects both the lung’s larger airways, called the bronchi, and the lung’s smaller airways, called the bronchioles. Treatment focuses on preventing asthma or stopping the inflammation, and relaxing the muscles that line the airways.
What causes asthma– not clear, but several environmental “triggers” have been identified. Most asthma triggers are allergens, substances that cause the immune system to overreact in most people. Common allergens include animal dander and saliva, pollens, molds, dust mites, cockroaches, some medications and certain foods.
Also high on the list of asthma triggers are viral infections, such as colds and influenza; exercise; breathing cold, dry air; environmental pollutants, such as cigarette smoke, wood smoke, paint fumes and chemicals; strong odors; and emotional stress. For some people with severe asthma, no specific triggers can be identified.
Asthma can develop early, normally often before age 5, but its symptoms can begin at any age. The condition has a genetic or inherited component and normally affects people with a family history of allergies.