Asthma
Definition
Bronchial asthma is the condition of subjects with widespread narrowing of the bronchial airways which changes in severity over short periods of time (either spontaneously or under treatment) and leads to cough, wheezing, and difficulty in breathing.
Cause
Asthma may be precipitated by exposure to one or more of a range of stimuli such as:
- allergens
- drugs (such as aspirin and other NSAIDs and beta blockers)
- exertion
- emotion
- infections
- air pollution
The onset of asthma is often early in life and may* be accompanied by other manifestations of hypersensitivity, such as hay-fever and dermatitis. Alternatively, the onset of asthma may occur in adulthood or even middle or old age. One possible contributory factor to the later onset of asthma is obesity which some people only develop later in life.
* People who are described as having atopy, which is also called atopic syndrome, often have one or more of eczema (atopic dermatitis), allergic rhinitis (hay fever), allergic conjunctivitis, or allergic asthma. They may also be particularly susceptible to food allergies.
Effect (Symptoms)
Symptoms of asthma can include:
- breathlessness (e.g. having to gasp for breath)
- tight chest causing discomfort
- wheezing that results in a whistling sound when coughing or just breathing
Treatment
Treatment is commonly with bronchodilators, with or without corticosteroids, usually administered via aerosol or dry-powder inhalers. In cases of severe asthma bronchodilators may be administered via a nebulizer. Oral corticosteroids are reserved for patients who fail to respond adequately to these measures. Severe asthmatic attacks may need large doses of corticosteroids. Avoidance of known allergens, especially the house dust mite, allergens arising from domestic pets, and food additives, will help to reduce the frequency of attacks. Asthma sufferers who smoke are generally also advised to reduce or cease tobacco smoking.
See also a list of diseases and disorders of the respiratory system (info all on one page).
