No one really knows exactly what causes asthma. In asthma, the irritation of your ultrasensitive airways results to the three changes:
- cells in your air passages produce excessively thick and sticky mucus that tends to clog your airways
- your air passages swell or become inflamed
- the muscles in your airways constrict and tighten
These changes cause your air passages to narrow or cnstrict, causing difficulty in breathing, wheezing, and tightness in the chest.