Definition: Your immune system is a set of cells and proteins that work together to protect your body from substances that are seen as threats, such as bacteria and viruses.
The immune system does a lot of good in keeping you healthy. However, in people who have allergies and asthma, the immune system treats pollens and other triggers – which are not normally harmful – as threats and produces an overreaction in the body.
The result is asthma symptoms, such as wheezing, coughing, chest tightness, and shortness of breath.
Pronunciation: ihm-YOUN SYS-tem
Examples: Whenever Judy would pet her sister's cat, her immune system would kick into gear and before she knew it, she was sneezing and wheezing.
