What is asthma?

Asthma is a chronic inflammation of the bronchial tubes (airways) that causes swelling and narrowing (constriction) of the airways. The result is difficulty breathing. The bronchial narrowing is usually either totally or at least partially reversible with treatments.

Bronchial tubes that are chronically inflamed may become overly sensitive to allergens (specific triggers) or irritants (nonspecific triggers). The airways may become "twitchy" and remain in a state of heightened sensitivity. This is called "bronchial hyper-reactivity" (BHR). It is likely that there is a spectrum of bronchial hyper-reactivity in all individuals. However, it is clear that asthmatics and allergic individuals (without apparent asthma) have a greater degree of bronchial hyper-reactivity than non-asthmatic and non-allergic people. In sensitive individuals, the bronchial tubes are more likely to swell and constrict when exposed to triggers such as allergens, tobacco smoke, or exercise. Amongst asthmatics, some may have mild BHR and no symptoms while others may have severe BHR and chronic symptoms.

Asthma affects people differently. Each individual is unique in their degree of reactivity to environmental triggers. This naturally influences the type and dose of medication prescribed, which may vary from one individual to another.

From the past to the present

Physicians in ancient Greece used the word asthma to describe breathlessness or gasping. They believed that asthma was derived from internal imbalances, which could be restored by healthy diet, plant and animal remedies, or lifestyle changes.

Allergy jargon

Asthma is derived from the Greek word Panos, meaning panting.

Chinese healers understood that xiao-chiran, or "wheezy breathing," was a sign of imbalance in the life force they called qi. They restored qi by means of herbs, acupuncture, massage, diet, and exercise.