When people with asthma come into contact with something they are allergic to, or something that irritates the lining of their airways (a trigger):
- The airways become narrowed making it more difficult to breathe.
- The muscles in the airways tighten, this is know as bronchospasm.
- The lining of the airways becomes swollen (inflamed) and sticky mucus (phlegm) may be produced.
This leads to asthma symptoms that may vary from person to person.
