Asthma is a disease, a chronic condition that is long-lasting and recurrent. The airways that are used in carrying air from the outside into the lungs are the organs of the body that are affected. People who constantly suffer from this condition are asthmatics.
Causes of Asthma
Allergies
Most common in all sufferers of asthma, allergies are a cause that is primarily predominant. About 25 percent of people who suffer from asthma have allergic rhinitis or hay fever that eventually leads to asthma. Antibodies in the blood (when allergies develop) trigger reactions that leads to the airways being inflamed and thereby leading to asthma.
Other allergens are animal proteins mostly from dogs and cats, cockroaches, dust mites and fungi. These are indoor allergens. There has been an increase in the exposure to these allergens due to the insistence on homes being energy efficient.
Tobacco Smoke
Smoking is a major cause among the reasons for developing asthma and leads to a higher risk of death as well. Wheezing, asthma and a whole host of respiratory issues happen due to tobacco smoke. With smoking, those who are exposed to second hand smoke and those children whose mothers smoke are at a higher risk of suffering from asthma. In addition, asthma is also very likely in adolescents who smoke.
Environmental Factors
Noxious fumes from paints, indoor cleaners, from mold, nitrogen oxide from stoves that use cooking gas are often causes for indoor asthma. With some people who use gas to cook, sulfur dioxide, pollution, nitrogen oxide, cold temperatures, ozone and humidity at high levels have been known to triggers in asthma.
Symptoms of asthma are increased by heavy pollution of the air since conditions that are smoggy cause the release of the destructive ingredient namely ozone and this causes problems such as cough and pain in the chest as well. The emission of sulfur dioxide that these conditions bring forth, and with a constriction of the airways, these result in asthma.Congestion may be a result of changes in the weather and cold air can trigger congestion of the airways, bronchoconstriction(constriction of the bronchi in the airways), decrease in the mucociliary clearance (another type of inefficiency of the airways) and secretions. Difficulty in breathing is also similarly caused by humidity.
Obesity
Adults with a body mass index (BMI) of 25 or 30 are overweight as compared to others and these people are likely to have asthma. When the BMI goes past 30, the risk of asthma is twice as great. In these cases, as research indicates, there may be a greater risk for asthma that is of a non-allergic type than that of an allergic type.
Pregnancy
The way of being born also influences the prevalence of asthma and babies that are born via Caesarean section are 20 percent more susceptible to asthma than those that are born vaginally.
When mothers smoke during pregnancy, children born to them have their pulmonary function that is lowered and this creates more of a susceptibility to asthma. Being prematurely born is also of risk for developing asthma.
Stress
High rates of stress have rates of asthma that are high due to the fact that stress modifies the immune system as well.
Genes
Genes are associated with asthma and out of the 100 genes or so that are asthma related, about 25 are associated, as of 2005, with separate populations. These play a major role in the management of the inflammation as well as the immune system in general and, it has been observed that these are the genes linked to asthma. Heredity accounts for about three-fifths of all cases of asthma and according to the Center for Disease Control (USA), parents with asthma indicate the risk in children by around three to six times.
The interaction of genes with factors in the environment have been well replicated as being associated with asthma – as in the exposure to the genetic trait CD14 (single nucleotide polymorphism (SNP) C-159T) have been well-replicated examples associated with asthma.
Airway Hyperreactivity
Another risk factor is airway hyperreactivity leading to asthma.
Atopy
Atopy is a class of general hypersensitivity due to allergies due to which different parts of the body are affected - different parts of the body that do not come in contact with allergens is a risk factor for developing asthma. Children, about 40 percent to 50 percent, with atopic dermatitis develop severe and persistent asthma as they become adults.