Affecting 300 million people, asthma is the most common chronic disease in the world. But its origin remains partly mysterious. It is estimated today that this disease does not have a single cause but stems from several factors.
Genetic predisposition, allergies, respiratory infections, passive smoking… Discover the factors favouring the appearance of asthma.
Asthme facteurs favorisantsAsthma is related to hereditary factors, as sometimes evidenced by a large number of people within the same family. Studies on twins and sick families stressed a significant genetic influence in its development. Have a double asthmatic parent indeed the risk to suffer also. But it is impossible to say it is a hereditary disease, because there is no single gene responsible. In the context of this heterogeneous disease, the contribution of a single gene appears even minimal.
It is estimated that several genetic abnormalities are able to increase the risk of developing the disease. Related to specific environmental conditions, they can induce excessive sensitivity of the bronchi. To learn more about these genetic influences, check out our article “asthma gene unmasked”.
The leading role of allergy
Asthma is a chronic inflammatory disease of the bronchial tubes, often maintained by allergic factors: mites, dust, pollen… If crises are caused by allergens, then one can speak of allergic asthma. It is the most common form in children (more than 85% of childhood asthma and more than half of adult asthma). Thus, a personal allergic field (hay fever, allergic conjunctivitis, eczema…) is conducive to disease.
An allergic family plot will also increase the risk of suffering from asthma. A child is more likely to have allergic events if one of the parents is reached (27%) or both (50%) against only 10% if none is ill. But the role of heredity is not absolute and a case of asthma may appear in a family that has never been hit by any allergic disease.
Other contributing factors
Respiratory infections to repetition and passive smoking are also accused of promoting the development of asthma. Gastroesophageal reflux disease (GERD) is also under investigation. This upwelling acidic gastric contents could maintain a bronchial hyperresponsiveness. The influence of psychological factors on the onset of the disease remains controversial.