<s>[INST] What is airway remodelling? [/INST] Airway remodelling may occur when asthma is not treated or controlled effectively as long term airway inflammation may result in permanent changes in the airways. The actual structure of your airway walls can change causing blockage that can’t be completely reversed with treatment.

Asthma is defined as “a chronic inflammatory disease of the airways” and is characterized by reversible airway obstruction. Irreversible airway obstruction may develop due to the alterations in airway structure that occur with airway remodeling.

Airway remodelling is an ongoing process in reaction to inflammation as the body activates a process in an attempt to repair the lungs in response to persistent inflammation. This leads to permanent structural and functional changes. Much as a skin wound leads to scar tissue formation (this has a different structure from surrounding skin); airway remodelling results in different airway characteristics. The cells (epithelial) that line the airway are damaged and the basement membrane underneath the epithelial cells becomes thicker. More blood vessels are formed and the amount of smooth muscle surrounding the airway increases. The airways loose elasticity, the walls thicken, and excess muscle results in bronchoconstriction and long term loss of lung function, a worsening of asthma and the development of fixed airflow limitation.

Airway remodelling may be, at least somewhat, reversible and preventable. The number of asthma attacks has been associated with greater decline in lung function and a higher risk of airway remodeling. Treatments for asthma may play a significant role by reducing asthma exacerbations resulting in preventing the decline in lung function and airway remodeling. It is extremely important for you to learn how and why your medications work.

The current treatment of asthma is aimed toward decreasing airway inflammation, reducing symptoms, and improving lung function. The use of controller/anti-inflammatory medications reduces the inflammatory process associated with asthma and thus results in less remodelling. A return toward normal airway structure has been found when proper and regular anti-inflammatory treatment is followed.  Source: Asthma Canada. Link: https://asthma.ca/get-help/understanding-asthma/frequently-asked-questions/. Field: Lung Disease. Disease: Asthma </s>