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Asthma is a chronic disease that affects the airways. Asthma sufferers experience swelling of the airways and excess mucus production, resulting in narrowing of the airways. When we inhale, air travels through the airways and makes its way to the alveoli. This is where the exchange of gas takes place between oxygen, which is needed by the body’s cells, and carbon dioxide, a waste gas that is carried out of the lungs.


The exact cause of asthma is not known. It would appear however, that having a family history of asthma and other factors, such as allergies, may play a role.

Asthma is an exaggerated reaction by the airways to a foreign substance (allergen), including dust and pollen, and resulting in airway swelling. Other factors that may cause this type of swelling are smoke, air pollution and respiratory infections (cold, flu).

The airways are surrounded by muscle. These muscles, made more sensitive when the airways are inflamed, react by constricting, making the airways even narrower. This is known as bronchospasm. Factors that can lead to muscle constrictions are sudden temperature changes (cold air and humidity), strong odours, exercise, and stress.


Bronchial inflammation and bronchospasm obstruct the flow of air, causing the following symptoms:

• difficulty breathing;
• shortness of breath;
• coughing;
• wheezing;
• chest tightness;
• bronchial secretions;
• rapid breathing in young children.

The intensity of asthma symptoms varies from person to person and can vary over time as well.


The first step in diagnosing asthma involves a medical examination performed by a doctor, and a questionnaire about your symptoms. The doctor may also want to test your pulmonary function to see how well your lungs are working. Additional tests such as allergy skin tests, blood tests or chest x-rays may also be ordered.


There are two categories of asthma medications: Controllers and Relievers.

Controllers are anti-inflammatories that are used to prevent and reduce inflammation inside the air passages. Control medications are the cornerstone of asthma management. They work slowly and should be taken regularly, even when asthma symptoms have disappeared. They help prevent asthma symptoms, reduce exacerbations as well as asthma-related hospitalizations and deaths. Corticosteroids are the most commonly used controller medications prescribed for asthma. Other controllers may be part of the asthma treatment plan. They are used as adjuvant therapy in combination with corticosteroids. They can be administered as an inhaler (pump), a liquid or a pill.

Relievers are bronchodilators. They are also known as “rescue” medications because they are used in emergency situations. They work quickly and their effects are felt within minutes. They work by relaxing the muscles around the airways. They are used as needed in the treatment of asthma attacks and to prevent exercise-induced asthma. Using a reliever less than four times a week is one of a sign that asthma is controlled.

Dosage adjustments can be made according to the action plan established with the doctor, and based on close monitoring of symptoms and regular measurements of peak expiratory flow rates.

Proper technique

Ensuring a proper inhaling technique is important as it will provide better efficacy. Your pharmacist can show you how to obtain the best results. He or she may also recommend the use of a spacer and metered dose inhaler, making it easier for you to take your medication.


The key to preventing asthma attacks is to avoid your asthma triggers:

• Allergens;
• Respiratory infections including colds and the flu (a yearly flu vaccine is recommended);
• Big changes in ambient air temperature;
• Cold air (asthmatics should cover their nose and mouth when participating in outdoor activities when it is cold);
• Emotional and stressful situations (use relaxation techniques);
• Smoke (smoking cessation treatments are available);
• Exposure to smoke, strong odours and air pollution (purify indoor air);
• Certain medications (speak to your pharmacist or doctor before taking any medications, even if they are natural or over-the counter products).

For more information:

Canadian Lung Association; | Allergy / Asthma Information Association;

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The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.