What respiratory disorder is characterized by a decrease in lung elasticity and over-inflation of the lungs?

Emphysema is characterized by a decrease in lung elasticity and over-inflation of the lungs due to the destruction of the elastic fibers in the alveoli. This condition leads to an increased volume of air trapped in the lungs, making it difficult for an individual to expel air effectively. The loss of elasticity prevents the alveoli from returning to their original shape after inhalation, resulting in hyperinflation. Patients often experience symptoms such as shortness of breath and a chronic cough. This condition is a form of chronic obstructive pulmonary disease (COPD) and is primarily associated with long-term exposure to irritants, such as cigarette smoke, that damage the lungs.

In contrast, other respiratory disorders listed do not exhibit the same mechanism of alveolar destruction and resulting lung over-inflation. For instance, asthma is characterized by reversible airway obstruction and inflammation, pneumonia is an infection that causes inflammation in the alveoli, and chronic bronchitis involves persistent cough and mucus production due to airway inflammation, but does not typically involve the destruction of alveoli seen in emphysema.