What causes asthma?
Scientists have not pinpointed the underlying condition that causes people to be susceptible to asthma attacks. They do know that asthma is strongly associated with allergies, especially in children; about three-quarters of people with asthma also have allergic rhinitis (hay fever). Asthma also seems to have a genetic component. If both your parents have had asthma, you’re more likely to get it, too.