In spite if its prevalence, medical professionals develop dissimilar definitions of asthma. Health care authorities have quire broad definition that takes into account different factors. For instance, the National Heart, Lung and Blood Institute defines the ailment as: "a chronic inflammatory disorder of the airways (which causes recurrent episodes of wheezing, breathlessness, chest tightness and coughing, particularly at night or in the early morning) usually associated with widespread but variable airflow obstruction that is often reversible, either spontaneously or with treatment" (Evans et al, 1997, p.157).
Organizations directed basically toward the satisfaction of informational needs and research, developed another definition which is more understandable for patients. The American Lung Association thus writes that asthma is: "a chronic disease of the lungs in which the airways overreact to certain factors by becoming inflamed or obstructed, making it difficult to breathe comfortably." (ibid, p.158). Several organization view asthma as rather a complex of related diseases than a single ailment. In fact, asthma is a state of lungs in which bronchial airways react to different stimuli with inflammation. The mentioned stimuli, also known as asthma triggers, vary broadly and might include a spectrum from cold air to physical exercise and emotional outburst.
Swelling of the bronchial tubes is followed by their constriction and narrowing, so that the person is barely able to inhale. Furthermore, bronchoconstriction (Ducharme et al, 2003) leads to the other unpleasant symptoms, such as wheezing, coughing, sneezing and tightness in chest. "Some people suffer asthma symptoms continuously; others experience them only if exposed to triggers. Regardless of the cause, severe asthma is a serious health concern that can lead to respiratory failure and death" (Wolfenden et al, 2003, p.232).
The scholars still debate over the cause of the ailment. Research, conducted by Canadian Asthma Prevention Institute, suggests that heredity and genetic factor play foremost role in the development of the disease and the emergence of the scope of symptoms (asthmaworld.org, 2006). For instance, there is a strong connection between the disease and atopy, the high concentration of antibodies, responsible for allergic reactions, in blood. Vulnerability to environment polluters in this case increases the risk of asthma. The most widespread allergens are microscopic parts of dust mites, plants and flowers, animal dander, aerosols and enzymes (Evans et al, 1997).
Earlier research shows that external factors are foremost contributors to the development of the ailment (asthmaworld.org, 2006). Exposure to aforementioned allergens as well as to occupational irritants (fumes, tobacco smokes, vapors) and medications (the most common medicine against hypertension, tachycardia and glaucoma - beta-blockers) might induce severe symptoms and fits. According to the same research report, from 5 to 20 per cent of people suffering from asthma are sensitive to aspirin, naproxen and indomethacin and to sulfites (substances used in food industry to preserve canned fish, dried apples, salads and berries). In addition, the most common allergen constitutes red and orange fruits and berries, such as cherries, oranges, lemons, strawberries and so on.
Another group of influential factors includes virus infections,