<s>[INST] Why do more people have asthma now than in the past? [/INST] It seems there are more cases of asthma today because it is more correctly diagnosed than it was in the past.That said, the overall incidence of asthma has been increasing. While researchers do not know exactly why, they do have several theories.One theory suggests that more people develop asthma today because we spend more time indoors than people used to. Indoor air can contain a number of asthma triggers, such as smoke, dust mites and pet allergens. Additionally, in response to the oil crisis of the 1970s, modern homes are more tightly sealed than older homes. This means that indoor air doesn’t circulate with outdoor air the way it did in older, better-ventilated homes. As a result, people inside are exposed to greater amounts of indoor air and the triggers it may contain.Other theories attempting to explain why asthma is on the rise include the suggestion that outdoor air pollution has a significant effect on asthma. There is also the possibility that because children today experience fewer infections, they are somehow more susceptible to developing asthma. Source: AIM. Link: https://getasthmahelp.org/adult-faq.aspx. Field: Lung Disease. Disease: Asthma </s>