Asthma Causes - What Causes Asthma (Asthma Etiology)

What causes asthma is not fully known. Inspite of advances in the medicine, we still don't exactly know the causes (etiology) of asthma.. We, however, do have some evidence about several suggested factors which may be the cause (etiology) of asthma. Whatever the cause (etiology) of asthma is, one thing is common for all asthma patients; there is constriction of the airways (the passages which transport air into and out of the lungs). Also, irrespective of the cause (etiology) of asthma, the symptoms of asthma are the same in all asthma patients.

Understanding the causes (etiology) of asthma is not only important for preventing asthma (if you don't have asthma) but, it also plays a key role in preventing the asthma symptoms from getting worse (if you already have asthma). So, understanding causes (etiology) of asthma is a must, especially if you or your child already have asthma.

The suspected causes (etiology) of asthma cause asthma in some people but, not in others. Why some people develop asthma because of these factors and not others is still not known.

Though less is known about the causes (etiology) of asthma, it is widely believed that asthma is caused by interplay between your genetics and some environmental factors (described below). It means that two factors play main role in the development of asthma:

• Your genetics

• Exposure to some specific environmental factors

Now lets throw some light on the possible causes of asthma.

Possible causes of asthma (asthma etiology)

The Hygiene Hypothesis - Asthma Causes

According to this interesting hypothesis, reduced exposure to a wide variety of different bacteria and virus types in modern societies deprives our immune system of the ability to distinguish between harmless and potentially harmful irritants. This hypothesis blames our "super-clean world" to be a possible cause (etiology) of asthma. To say this in other words "it is exposure to germs that actually prevents asthma".

This theory is supported by the fact that children living in less hygienic conditions tend to have lower incidences of asthma. 

Additionally, studies which show that upper respiratory tract infections are protective against asthma risk also tend to show that lower respiratory tract infections conversely tend to increase the risk of asthma

Genetics - Asthma Causes

Asthma runs in families which suggests that genetics may be a cause (etiology) of asthma. It means that if you have asthma it is likely that:

• One or both of your parents might have asthma.

• One or more of your siblings might have asthma.

• You may pass the asthma disease to your children.

Heredity accounts for about three-fifths of all cases of asthma. If you have asthma, your children are three to six times more at risk of developing asthma than the people whose parents don't have asthma.

Gender - Causes Of Asthma

Before puberty, asthma is more common in males than females. But after puberty, asthma becomes more common in females than females. Probably hormones are responsible for this (some hormones differ between males and females). But it is still not known which hormones affect asthma.

Respiratory Infections - Causes Of Asthma

Though the hygiene hypothesis says that reduced exposure to germs is a cause (etiology) of virus, there is also some evidence which shows that exposure to some viruses may cause asthma.

Respiratory syncytial virus (RSV) causes bronchiolitis in children; after bronchiolitis some children are known to develop asthma, which suggests that Respiratory syncytial virus (RSV) may be a cause of asthma.

Respiratory infections such as rhinovirus, chlamydia pneumonie, and Bordetella pertussis cause asthma exacerbations.

Obesity - Asthma Causes

Obesity may be a cause (etiology) of asthma; it is supported by the facts that:

• Asthma is more common in obese and overweight people.

• Asthma is more severe in obese and overweight people.

Studies have shown that if an asthma patient loses weight, it not only decreases asthma symptoms in them but also reduce dependence on corticosteroids (asthma medications).

Vitamin D Deficiency - Asthma Causes

Though not confirmed yet, it is suggested that vitamin D deficiency may be a cause (etiology) of asthma. It is supported by two facts:

1. Asthma involves inflammation of airways, and vitamin D has anti-inflammatory properties.
2. Asthma is more common in people living in parts of the world with lower vitamin D intakes.Obesity
   

Air Pollution - Causes Of Asthma

It has been observed that the incidence of asthma tends to be higher in people living in a polluted environment.

Lack Of Exercise - Causes Of Asthma

Apart from other benefits, exercise makes your airways stronger, thus making it more resistant to the harmful effects of asthma triggers.

Whatever the cause (etiology) of asthma is, the signs and symptoms of asthma are the same in all patients. Likewise, the treatment (management) of asthma is the same for all asthma patients irrespective of the cause (etiology) of asthma.