When you have ASTHMA, two factors cause your airways to narrow, reducing airflow into your lungs. This may result in symptoms such as wheezing, or shortness or breath.

The two factors are:

  1. Constriction of the airway muscles.
    Constriction of the circular airway muscles leaves the passage very narrow.
  2. Inflammation and swelling of the airways.
    Inflammation in your airway tissues leaves them red and swollen. The swelling also leads to a narrower airway.

Your airways may always be a little bit inflamed. If left untreated, it can lead to loss of lung function.