Asthma

What is asthma?

Asthma is a respiratory disease characterized by an inflammation of the airway, and reversible airway obstruction.

Symptoms may include coughing, wheezing, breathlessness and tightness in the chest. Asthma may be worsened by exercise and respiratory infections, and exposure to allergens, air pollution and cold air.

Asthma is one of the most prevalent chronic conditions in Canadian children, and it is also a serious problem for adults. In Canada, 8% of adults and 12% of children are asthmatic. The exact cause of asthma is still unknown, but it appears to be the result of a complex interaction of three factors:

1. Atopy: the tendency to have allergic reactions.
2. Exposure to allergens such as dust mites, cat and other animal dander, cockroaches and moulds.
3. Irritants and inflammation of the airways, following a respiratory infection, or irritation from tobacco smoke or other air pollutants like ozone.

In addition, heredity plays a role in the development of asthma. If you have asthmatic family members, you are more likely to develop the disease yourself.

Indoor Air Quality and Asthma

It is well known that poor indoor air quality increases the severity and the frequency of respiratory symptoms experienced by asthmatics. Pollutants that can aggravate asthma include the following:

• Biological pollutants such as mould and house dust mites.
• Irritating chemical pollutants such as nitrogen dioxide, ozone and formaldehyde.

Dust mites are the only indoor air pollutants that are recognized to cause asthma in otherwise healthy people. Other pollutants such as mould and nitrogen dioxide, however, are suspected of increasing the risk of developing asthma. With this in mind, it is therefore advisable to avoid exposure to these pollutants as much as possible, even if you are not asthmatic.

Where can I get more information?

Health Canada Resources

• It's your Health: Asthma

Other Resources

• Public Health Agency of Canada: Asthma
• CMHC: Fighting Asthma In Your House