On Asthma

Asthma is a lung disease that causes obstruction of the airways. It is an overreaction of the body’s immune system usually caused by exposure to an allergen, a substance that the body perceives as foreign and dangerous.

During an asthma attack, spasms in the muscles surrounding the bronchi (small airways in the lungs) constrict, impeding the outward passage of air. Asthma sufferers often describe this plight as “starving for air”. Typical symptoms of an asthma attack are coughing, wheezing, a feeling of tightness in the chest, and difficulty breathing. An attack can last for a few minutes or several hours.

The spasms characterizing an acute attack are not the cause of the disorder, but a result of chronic inflammation and hypersensitivity of the airways to certain stimuli. An attack can be triggered if a susceptible individual is exposed to an allergen, but irritants, infection, stress, exercise, use of aspirin, ibuprofen, naproxen, or other NSAIDs – or even rapid changes in weather and humidity- can trigger an attack.

Common asthma provoking allergens include animal dander, cockroach allergens, pollens, mold, pet dander, chemicals, drugs, dust mites, environmental pollutants, feathers, food additives ( such as monosodium glutamate, sulfites such as sodium metabisulfite), sea food, dairy products, nuts, yeast-based food, fumes, mold, and tobacco smoke.

Factors that can trigger non allergic asthma include adrenal disorders, anxiety, temperature changes, exercise, extremes of dryness or humidity, fear, laughing, low blood sugar, and stress. A respiratory infection like bronchitis is the most common provoker. Whatever the particular instigator, the bronchial tubes swell and become plugged with mucus. This inflammation further irritates the airways, resulting in even greater sensitivity. The attacks become more frequent and the inflammation more severe.

Asthma epidemics related to atmospheric contamination – situations in which dust and chemical particles are abundant, especially in enclosed environments- are well known. Occupational exposure to certain substances, such as urethrane and polyurethrane, used in the adhesives and plastic industry, along with rubber epoxy resins from paint, textile cleaner’s fumes, dry cleaning chemicals, and others also may be major risk factors.

Asthma symptoms may resemble those of other diseases, such as emphysema, bronchitis, heart burn, and lower respiratory infections.

Common signs and symptoms of asthma include: recurrent wheezing, coughing, trouble breathing, chest tightness, symptoms that occur or worsen at night, symptoms that are triggered by cold air, exercise or exposure to allergens.

Wheezing — high-pitched whistling sounds when you breathe out — is one of the main signs of asthma and indicates obstructed airways.

Although your symptoms, medical history and physical examination may suggest that you have asthma, lung (pulmonary) function tests may be needed to confirm an asthma diagnosis. Lung function tests may include one or more of the following tests:

a. Spirometry

This noninvasive test measures how well you breathe. During spirometry, you take deep breaths and forcefully exhale into a hose connected to a machine called a spirometer. Spirometry testing reveals two measurements that are important in diagnosing asthma:

Forced vital capacity (FVC), which is the maximum amount of air you can inhale and exhale.

Forced expiratory volume (FEV-1), which is the maximum amount of air you can exhale in one second.

The two measurements are compared. If certain key measurements are below normal for a person your age, it may be a sign that your airways are obstructed. Your doctor may ask you to inhale a bronchodilator drug used in asthma treatment to open obstructed air passages and then try the test again. If your measurements improve significantly, it's likely that you have asthma. Your doctor may still suspect that you have asthma even if your initial spirometry measurements are normal. If so, you may need additional tests.

b. Challenge test

During this test, your doctor deliberately tries to trigger airway obstruction and asthma symptoms by having you inhale an airway-constricting substance or take several breaths of cold air. If you appear to have exercise-induced asthma, you may be asked to do vigorous physical activity to trigger symptoms.

After triggering your symptoms, you retake the spirometry test. If your spirometry measurements are still normal, it's likely that you don't have asthma. But if your measurements have fallen significantly, it may mean you have asthma.

On Wednesday, April 15, we'll deal with nutrients, herbs, and other traditional approaches in the management of asthma.