The immune system's main role is to defend the body against harmful invaders such as viruses and bacteria. However, in individuals with asthma, this system can become hypersensitive. When exposed to common allergens like pollen, dust mites, or pet dander, the immune system overreacts. https://www.evernote.com/client/web#/notes/63dc0fff-1f71-9285-28c9-0d22c2c51a4f?fs=true