Asthma

Asthma is a chronic disease in which the air passages, or bronchi, overact to normally harmless substances or circumstances. When these triggering factors enter the bronchi, the airways constrict to hinder the flow of air in and out of the lungs. Very soon, the bronchi become inflamed, and the membranes lining them secrete a sticky mucus. The result is wheezing, coughing, and difficulty in breathing. A severe attack can be life threatening. Asthma triggers vary from person to person; some of the most common are allergens such as pollen, animal dander, and house dust; irritants such as air pollution, tobacco smoke, perfumes, and chemicals; cold air; certain foods and food additives; aspirin and related medications; anxiety and stress; and vigorous exercise. No one knows why some people develop hyper reactive lungs, although an inherited predisposition appears to playa role. Many people think that emotional problems are a major cause, but researchers have discounted this. Asthma is a difficult disease that may lead to emotional problems, and stress can sometimes provoke a flare up, but it is not itself a psychological disorder. Although asthma differs from an allergic reaction, allergies are often involved and can also trigger attacks. Most common in children, asthma often subsides during adolescence, but never fully disappears. It is not unusual for adults to suffer a recurrence after going years without a flare-up. This return often as not comes on the heels of a respiratory infection.

Diagnostic Tests and Procedures

Wheezing and other symptoms may point to asthma, but lung function tests will still be necessary to distinguish it from other disorders. Testing begins with spirometry to measure the amount of air that is breathed in and out of lungs under different circumstances. Spirometry is sometimes combined with challenge testing to identify the specific asthma triggers and to measure the effectiveness of medications. In a challengetest, the patient is exposed to a suspected trigger and its effect is then measured by spirometry.

Medical Treatments

Doctors approach asthma treatment with two major goals: to prevent attacks and to reverse any flare up as quickly as possible. Prevention entails teaching patients how to control their disorder with drugs, lifestyle changes, and, increasingly, alternative therapies. Asthma patients are also taught to use a peak flow meter, a simple hand held device that measures the amount of air that can be exhaled after taking a deep breath. A drop in the normal peak flow reading points to an imminent attack; an increase indicates that therapy is working. Prompt treatment with bronchodilator drugs to open the airways during an asthma attack can usually stop it before it becomes an emergency. The most common prescription medications for asthma are.

Beta 2 Agonists

These drugs, most of which both prevent and stop attacks, are the most widely used asthma medications in the United States. Included are albuterol (Proventil and Ventolin), isoetharine (Bronkometer), metaproterenol (Alupent and Metaprel), and terbutaline . Available in pill, liquid, and aerosol forms, they work by relaxing the muscles that control the airways. They also reduce the flow of mucus by inhibiting histamine production, and help to clear mucus from the lungs. Their side effects include shakiness, tremor, and an increased heart rate; long term use can cause anxiety and restlessness. Another drug in this class, epinephrine (Adrenalin), is inhaled or injected, and works faster and more forcefully than other beta 2 agonists. It is usually reserved for severe attacks that are not controlled by the other medications.