Obstruction is caused by three mechanisms:
- inflammation of the inner bronchial wall;
- contraction of the muscle fibers surrounding the bronchi (bronchoconstriction);
- overproduction of mucus (thick secretions) clogging the bronchial tubes.
When a person experiences one or more of these symptoms, he/she is said to be having an “asthma attack”. A severe asthma attack can be a terrifying experience accompanied by sensations of suffocation, shortness of breath and loss of control. As a result, poorly-treated or underestimated asthma can put a person’s life in danger.
The precise causes of asthma have not been completely determined, but the disease appears to be the result of a complex interaction between several genetic (hereditary predisposition) and environmental factors.
Asthma triggers may vary from one person to the next. It is therefore important for any sufferer to identify the elements likely to lead to the appearance of symptoms.
Factors triggering asthma symptoms
- sudden temperature changes (cold air and humidity)
- tobacco smoke (also an inflammatory factor)
- strong odours (cleaning products, perfume)
- the quality of indoor and outdoor air
- workplace irritants (occupational asthma)
- colds and viral respiratory infections
Irritants cause a contraction of the respiratory tract (bronchoconstriction). Because of the irritation, the tiny muscle fibres surrounding the bronchi are stimulated, squeeze the respiratory tract and prevent air from circulating properly.
The symptoms of bronchoconstriction produced by irritants are usually immediate, short lasting and reversible thanks to the use of rescue medicine (bronchodilators).
Les facteurs inflammatoires
- Allergens: mites, food allergies, animals, mold spores, pollens etc.
- Respiratory infections: colds, flu, sinusitis, bronchitis, pneumonia, etc.
- Tobacco smoke: being a smoker or being exposed to second-hand smoke
The symptoms produced by inflammatory factors may appear more gradually. They can trigger or increase asthma symptoms over a period of several weeks, or even months, and are not as easily reversible.
Persons at risk
People at risk for developing asthma are:
- People with a family history of asthma
- People born prematurely
- People with gastroesophageal reflux disease
- Children who have had severe and repeated respiratory infections (eg, pneumonia, rhinovirus or syncytial virus, etc.)
- People with obesity
- People exposed to potentially irritating environmental factors (eg, farmers, painters, etc.)
Signs and symptoms
Bronchial obstruction may cause the following symptom (s):
- Shortness of breath;
- Chest tightness;
- Of the cough
- Secretions (mucus)
- persistent cough after a cold (especially in children)
The respiratory tests frequently used to diagnose and monitor asthma are spirometry and peak flow measurement. These are simple tests that measure, among other things, the maximum amount of air that you can breathe out and the rate at which you can do so.
A spirometry is performed in a doctor’s office, clinic or hospital by a healthcare professional. It provides data and several measurements that can help establish a diagnosis or monitor the progression of the disease.
You can measure your own peak flow (PF) with an inexpensive and easy-to-use device. By keeping a regular record of your PF measurements, you can monitor the management of your asthma and validate the effectiveness of your medication.
People with asthma should be able to lead a normal life. To do so, there are several drugs that help manage and prevent the symptoms of asthma. The following distinguishes between drugs used in the event of an asthma attack (rescue medication) and drugs used on an everyday basis (maintenance medication).
This medication is used to relieve the immediate or acute symptoms of asthma. It is therefore taken in the event of an attack. Most rescue drugs are short-action bronchodilators. They are fast-acting (a few minutes) and serve to relax the muscle fibers surrounding the bronchi. The effects of the medication are felt for 4 to 6 hours.
This medication is taken on a regular basis. It includes long-acting bronchodilators and inhaled corticosteroids, which are used in the daily treatment of asthmatics. These two drug categories are often combined in a single device, but they can also be prescribed separately.
Long-acting bronchodilators are designed to relax the muscle fibers surrounding the bronchi. Their action lasts 12 to 24 hours. Inhaled corticosteroids on the other hand are designed to appease inflammation of the inner bronchial wall. Maintenance drugs are usually taken each day as a means of constant prevention.
Combination of inhaled corticosteroids and long-acting bronchodilators:
Over 50% of asthmatics manage their illness inadequately, although many believe they are in control. The result is observed in the form of daily symptoms, more frequent administration of rescue medication, ER consultations accompanied by frequent hospitalizations, as well as absenteeism from work or school.
Tips and prevention
Prise en charge et maîtrise des symptômes
Les spécialistes en asthme s’entendent pour dire que la meilleure façon de prendre en charge l’asthme est d’impliquer activement le patient dans son traitement. Bien que les médicaments pour traiter l’asthme soient très efficaces, le succès du traitement repose en bonne partie sur la compréhension de la maladie et la réduction des principaux facteurs déclenchants.
Voici les principales étapes vers une prise en charge optimale :
- Obtenez un diagnostic rapide et précis, basé sur votre histoire personnelle et sur des mesures objectives de la fonction respiratoire (spirométrie);
- Apprenez à reconnaître les symptômes de l’asthme et à bien les comprendre;
- Contrôlez votre environnement et évitez les facteurs déclenchants;
- Assurez-vous de bien comprendre le fonctionnement de votre médication de secours et de l’utiliser telle que prescrite;
- Assurez-vous de bien comprendre le fonctionnement de votre médication d’entretien quotidien et de l’utiliser telle que prescrite;
- Élaborez un plan d’action personnalisé avec votre médecin;
- Réévaluez régulièrement la maîtrise de votre asthme par les tests respiratoires requis (spirométrie, débit expiratoire de pointe, etc.).
Voici les principaux critères d’un asthme bien maîtrisé :
- Vous ressentez des symptômes diurnes (le jour) moins de 4 fois par semaine;
- Vous ressentez des symptômes nocturnes (la nuit) moins de 1 fois par semaine
- Votre niveau d’activité physique est normal;
- Vous ne faites pas preuve d’absentéisme au travail ou à l’école à cause de l’asthme;
- Vous utilisez votre bronchodilatateur de secours moins de quatre fois par semaine;
- Les résultats de lecture de votre débit expiratoire de pointe (DEP) se situent dans les valeurs normales recommandées par votre médecin.
Asthmatic children can exhibit a variety of symptoms, such as a persistent cough following a cold, or difficulty breathing while engaging in physical activity, running in cold temperature conditions, following exposure to an allergen. Others will develop a cough and daily shortness of breath. These symptoms can vary over the course of a day, and from one day to the next.
It is essential that you identify and eliminate the factors triggering or aggravating your child’s asthma, and make his/her environment healthier. By doing so, you will improve your child’s quality of life, reduce the frequency and intensity of his/her symptoms, avoid absenteeism from school and hospitalizations, while decreasing the need for medication.
Some of the factors triggering your child’s asthma can be avoided, while others can be minimized by taking adequate precautions. The following are a few practical tips. Bear in mind that triggers vary from one child to the next.
- Avoid exposing your child to second-hand smoke, by not smoking. Avoid using a wood stove that produces smoke;
- Avoid exposure to irritants such as the fumes from paint, cleaners and perfumes;
- Remove carpets, dust the furniture and clean the floors with a damp cloth (to avoid raising dust);
- Avoid vacuuming or cleaning the house while the child is present;
- Eliminate mould on plants or in rooms plagued by excessive humidity or water infiltration;
- Maintain the ambient relative humidity rate between 40 and 50%. Avoid sudden humidity variances;
- Avoid feather pillows and bed covers; preferably, select bedding that is hypoallergenic and washable. Clean the bedding once a week. Cover the mattress with a waterproof fabric or a special casing;
- Avoid stuffed or woolen animals. Wash fabric toys regularly. Choose toys that are hypoallergenic or stuffed with foam rubber.
- If your child is allergic to animals, it would be wise not to have pets or birds in the house, and to avoid all contact with these. Remember that there is no such thing as a non-allergenic pet.
Physical activity and sports:
- Most asthmatic children can practice their favourite sport without restriction, as long as their asthma is properly managed. They simply have to progress at their own pace and respect their limits. If need be, children can use their bronchodilator (rescue medication) 15 minutes before their exercise, to prevent shortness of breath.
- Asthma is not caused by psychological factors, but, in certain cases, strong emotions can trigger an asthma attack. When children are angry, get them to calm down; encourage them to talk and verbalize their emotions. It is essential that children learn to manage their stress and emotions.
- Make sure your child understands his/her illness, symptoms and treatment;
- Discuss the matter with the teacher or educator: provide them with information regarding your child’s illness, what triggers the latter, and the steps to take in case of an attack;
- Make sure your child always has his/her rescue medication close at hand.
Did you know that
The Quebec Lung Association offers direct services to the population. For more information, visit our Patient Resources section.