What Causes Asthma?

Asthma is a condition that affects the respiratory system, which is usually of allergic origin, resulting in difficulty in breathing, wheezing, and panting. Find out about what causes asthma here.
What Causes Asthma?
The term ‘asthma’ has been derived from an old Greek word which means ‘to pant’. It is basically a chronic condition which affects the air passages when they are stimulated by environmental factors or allergens that act as triggers. There are two particular ways that the air passages respond to asthmatic triggers: 1) hyperresponsiveness, 2) inflammation. When these responses occur, it results in the typical symptoms of asthma, such as coughing, wheezing, and dyspnea, or labored respiration.

Hyperresponsiveness: In this, when allergens or any other irritant are inhaled, it results in the smooth muscles in the air passages becoming constricted and getting excessively narrow. Constriction of the air passages when they are exposed to irritants and allergens is a normal reaction that occurs in everybody, however, in people with asthma it results in a special kind of hyper reactive response.

In those people who do not have asthma, when an irritant is inhaled, the air passages relax as well as open out in order to expel the irritant from the lungs. However, in those who have asthma, there is no relaxation of the air passages, and instead they become narrow, leading to the panting breath of asthma. It is though that there may be a defect in the smooth muscles of those who are afflicted with asthma, possibly a lack of some vital chemical, which prevents the relaxation of the muscles.

Inflammation: Inflammation follows the hyper responsive stage. When the air passages are subject to allergens or any other environmental triggering factors, the immune system kicks in, delivering immune factors like white blood cells to the area. These cause the air passages to become swollen, fill up with fluid, and produce a sticky, thick kind of mucus. These combine to cause breathlessness, wheezing, the inability to inhale or exhale adequately, and a cough that produces phlegm.

This inflammatory response seems to affect everybody afflicted with asthma, even mild cases.

So, What Exactly Causes Asthma?

While what exactly causes asthma is still not fully understood, however, research has shown that it can be triggered off by many factors, such as genetics, the childhood development s well as growth of the immune system and the lungs, environmental factors, and various types of infections.

Asthma and Genetics: Scientists and doctors accept the fact that asthma is a hereditary disease. But they have not been identify yet the genes, or gene, that are involved. It is thought that the genes that are associated with asthma are linked to the immune system and the lungs. It is widely known that ‘Atopic Diseases’, like Asthma, Allergic Rhinitis, and Dermatitis, occur in some form or the other in families.

Asthma and the Immune System: Research has revealed that the immune system of adults and children who have asthma responds quite differently compared to those without asthma. People who have asthma are generally allergic, and have allergic reactions to factors that cause no problems to others. The immune system of allergic people overreacts when exposed to ordinary substances like cat dander, mold, and pollens. Sometimes, the immune system could even overreact to bacteria and virus, increasing the chances of an asthmatic attack.

Asthma and Childhood: The initial months as well as years in the life of a child is a vital period during which he/she could become predisposed to developing asthma or develop it. This is due to the abnormalities in the development as well as growth of the lungs. Premature babies are particularly vulnerable to respiratory diseases and infections, since their lungs are not completely developed when they are born. Sometimes, an infection could lead to inflammation, thus injuring the tissues of the lungs.

Asthma and the Environment: There are several non-immunologic or non-allergic factors in the environment that can trigger off the onset of asthma. When a person susceptible to asthma is exposed to these irritants, like secondhand smoke, for an extended period of time, there are higher chances of them developing full-blown asthma. Some of the other such irritants are air pollution, paints, and indoor chemicals.

Research is still continuing to understand better how the above factors affect the development of allergies like asthma.

By Rita Putatunda
Published: 2/20/2008

Source: www.buzzle.com