The Physiological Risk Factors Of Asthma

The risk factors for asthma remain poorly understood, but it appears that asthma results from a combination of genetic and environmental factors. The strongest risk factor for asthma is atopy, an exaggerated response to the environment. In other words, the lungs of asthmatics tend to respond more intensely to stimuli like cat dander or wood dust. Atopy frequently runs in families, and people with asthma often have allergies or family members with asthma and/or allergies. The allergic reactions found in people with atopy can range from seasonal hay fever to eczema to asthma. People with atopy also have increased blood levels of immunoglobulin E (IgE), the chief mediator of allergic and asthmatic reactions. In fact, IgE plays such a critical role in asthma that, in general, the higher the IgE level, the more severe the asthma.

 

Without question, asthma runs in families; however, there are many asthmatics who do not have a family history of allergies or asthma. The claim that asthma most likely results from a combination of genetic and environmental factors means that some people are genetically more prone to develop asthma and will display symptoms if exposed to the proper environment. It appears that several genetic abnormalities are involved in asthma, which may, in part, explain the extreme variability among asthmatics.

 

Another major risk factor for asthma is exposure to tobacco smoke, especially as a child. Numerous studies have documented that children raised in the homes of smokers have a significantly increased risk of lung problems, especially asthma. Living near freeways or in large cities may also increase asthma risk, as several studies have shown a link between air pollution and the risk of lung disease.

 

Some researchers suspect that being first-born increases risk, whereas coming from a large family may actually decrease risk. Why this is true remains a mystery and is the subject of intense research. It is also suspected that certain respiratory tract infections in childhood can increase the risk of developing asthma later in life. Finally, emotions and asthma often go hand in hand. One study, which followed 5,231 adults for thirteen years, found that anxiety and depression increased the risk of developing asthma dramatically.

 

It is important to divide risk factors into those we can and those we cannot control. While many risk factors are beyond our control, whether or not you smoke and what you eat can be controlled.