Asthma is a disease that affects the bronchi. Ramifications of the trachea, bronchi are air leading to pulmonary recesses. Asthma means that bronchi narrows so that air flows with difficulties in both the inspiration and the expiration. Several factors may be the origin of this disease:

- Muscle fibers located around the bronchi to contract ( "spasm" bronchial)

- Lining is irritated and is congested

- Inside bronchi accumulates abnormally viscous mucus.

Characteristic to asthma is the important role played by bronchi muscle contraction. Spasm disappears within minutes after inhalation of specific drugs and airflow is significantly improved. This confirms the diagnosis of asthma along with other lung function tests.

Asthmatics complain of attacks of choking (dyspnea) often associated with an irritating cough, which very rarely may be the only symptom of asthma. Breathing may sometimes be slightly wheezing (wheezing). Most of those affected notice in what context their problems appear. These observations help to quickly find the origins and triggers of asthma.

For most children suffering from asthma and nearly half of adults, the disease cause is an allergy to some substance present in air. It is currently not clear why some people develop allergies to certain substances while others are spared. Allergic reaction causes inflammation of the bronchial mucosal through vasodilation and excess mucus secretion and leads to progressively bronchial muscle contraction. In addition, a number of substances are secreted, such as for example histamine, which triggers bronchial contraction. Other patients have other asthma triggers, non- allergic, but eventually the same kind of inflammatory phenomena is installed, which has the same consequences. These cases are however less known.

Predisposition to asthma and triggers of asthma attacks

Triggers are varied. In case of allergic asthma, breathing in an allergen (substances that cause allergies) can trigger a crisis. All asthmatics present a bronchi hyper-activity - which is a disease characteristic.

Bronchi shrink into contact with irritants such as:

- Cool and dry air;

- Physical exercise;

- Cigarette smoke (including that of passive exposure);

- Pollution;

- Stress;

- Respiratory infections (colds, flu).

Asthma is a prevalent chronic disease in children. During the last 50- 100 years has been a sensitive increase in the number of cases of allergies and asthma. Causes are unknown. Environmental factors and lifestyle seem to have an influence. Predisposition to allergies and asthma is hereditary, the disease often appears to many members of the same family. Also it is likely that many genes are responsible for this predisposition and also environmental factors seem to play a role in this disease.

When consulting a family doctor, patients often report the same triggers. The doctor performs a physical examination to exclude the existence of other diseases, and then some pulmonary tests, which will highlight bronchus narrowing.

Respiratory tests consist in total and rapid expiration air from the lungs after a maximal inspire. One can also see if bronchi diameter is normal or low. This functional test is then repeated after inhaling a bronchodilator medicine.

If the test is normal despite the problems described by the patient, the specialist has the opportunity to make a provocative test. This will highlight airway responsiveness characteristic of asthma. Identification of allergen triggers are processed by a GP or by an allergist. Asthma is confirmed when the disease responds favorably to treatment.