From Asthma.com: IF YOU HAVE ASTHMA, ASTHMA IS IN YOUR LUNGS WHETHER YOU FEEL IT OR NOT
Asthma is a chronic, or long-term, disease that inflames and narrows the airways of your lungs. Asthma causes a variety of symptoms that can worsen at any time, making breathing difficult. Unfortunately, there is no cure for asthma. Even when you are not having symptoms, you still have inflammation in your lungs. However, by working closely with your healthcare provider to manage your asthma, you may be able to help get your symptoms under control.