Why are some infants and toddlers more susceptible to getting asthma?
The process just described can be normal, up to a point. Everyone’s airways constrict somewhat in response to irritating substances like dust and mold. But in a person with asthma, the airways are hyperreactive. This means that their airways overreact to things that would just be minor irritants in people without asthma. To describe the effects of asthma, some doctors use the term “twitchy airways.” This is a good description of how the airways of people with asthma are different from those without the disease. Not all patients with hyperreactive airways have symptoms of asthma, though. We still do not know what causes some people to develop asthma. Research shows that a family history of asthma or allergies, a specific allergy in the child or cigarette smoking during pregnancy may increase the likelihood that a person will develop asthma early in life. One of the most common causes of asthma symptoms in children five years old and younger is a respiratory virus. Although both adults a
