Which of the following best describes asthma pathophysiology?

The pathophysiology of asthma primarily involves an exaggerated immune response to environmental triggers. In individuals with asthma, the immune system overreacts to allergens, irritants, or respiratory infections, leading to inflammation and hyperresponsiveness of the airways. This results in bronchoconstriction, which is the tightening of the muscles around the airways, causing symptoms such as wheezing, coughing, shortness of breath, and chest tightness.

The chronic inflammation also leads to the production of excess mucus, further obstructing airflow. Unlike other respiratory diseases characterized by a fixed obstruction, such as chronic obstructive pulmonary disease (COPD), asthma is often reversible upon removal of the trigger or with bronchodilator medication, highlighting its unique pathophysiological mechanism centered around immune dysregulation rather than structural lung damage.

Other options present different respiratory issues that do not accurately capture the essence of asthma's pathophysiology, as they focus on chronic obstruction or conditions influenced by external factors like smoking or exercise, which do not address the fundamental underlying process of asthma.