Although clear patterns do exist, the specific causes of asthma are far from straightforward. Research has established that the causes cannot simply be divided into allergic and non-allergic. Allergic asthma is triggered by allergens: substances capable of stimulating the body’s immune system into bringing about an allergic reaction.
Many other factors also come into play. These can be as diverse as emotional upsets, environmental stress and even exercise. Exercise induced asthma can be particularly severe if exertion occurs in cold, dry conditions.
Common Causes of Asthma
The causes of asthma are wide ranging. Some causes, however, are more commonplace than others. At the top of the list are specific allergens. People suffering specific allergy induced asthma are usually very aware of the offending allergen and try to avoid it.
Pollutants, dust, smoke, irritants, chemicals, viral infections, bacteria, stress, emotion and exercise are other frequently diagnosed causes.
Asthma and Allergy Facts
- Allergies cause approximately ninety percent of the cases of asthma in children under the age of sixteen.
- The causes in approximately seventy percent of sufferers under age 30 are allergy-related.
- Approximately eleven percent of the non-asthmatic population experiences exercise induced asthma. Many of these people have
allergies or a family history of allergies. - In the elderly, the condition can be missed easily, commonly blamed on a heart condition or another lung disease like bronchitis or emphysema.
Asthma in Children and Passive Smoking
Research has concluded that maternal smoking can seriously impair infant lung function, even before the child is born.
Experts agree that inhaled cigarette smoke increases the tendency of the respiratory tract to react to other asthma triggers. Babies and younger children are particularly vulnerable.
Possible Genetic Link
Research has uncovered several areas of the genome that may be associated with the inheritance and development of asthma. Recent data published in the journal Science characterizes a novel receptor, GPRA (which stands for G protein–coupled receptor for asthma susceptibility), which is thought to play a role in the inflammation observed in some forms of allergy and asthma. The discovery is important not only for providing insight into potential causes of the disease, but also for leading to the development of new treatment strategies.
So, is asthma hereditary? Not in itself, but the tendency or predisposition to develop the condition can be. It is believed that genetic susceptibility, combined with environmental factors, is what leads to asthma.
Expert opinions regarding the degree to which the condition is hereditary vary widely. One fact that all experts agree upon, though, is that the likelihood of becoming asthmatic increases significantly if one or both parents already suffer from the condition.
Asthma in Children: The Hereditary Link
Dr. Glennon Paul, in All About Asthma and How To Live With It, concludes that if neither parent suffers from asthma, the chance of their offspring becoming asthmatic is as low as 10 percent. The likelihood increases to 25 percent when one parent is asthmatic, and to 50 percent when both parents are.