Important question! Most young folks outgrow asthma without any serious lung damage. However, a portion of children and teens who have asthma will continue to have asthma as adults. Most of these individuals, despite having persistent asthma into adulthood, will not have significant lung damage. There is a chance of lung damage if you have chronic inflammation (which would be caused by undertreated asthma flares). One of the treatments for it is a steroid which, whether taken as directed for flares only or taken daily to prevent frequent inflammation, reduces the long-term negative effects of asthma.

So, to answer your question, it is possible to have lasting damage from asthma. It would happen if you have significant disease in childhood that is inadequately controlled, but this is rare as most outgrow asthma or asthma in adulthood is mild and intermittent.