What condition is characterized by both a "barrel chest" and impaired lung function?

Emphysema is characterized by the presence of a "barrel chest" and impaired lung function due to the destruction of the alveoli, which are essential for gas exchange. In this condition, the air sacs lose their elasticity and become enlarged, leading to difficulty in exhaling air from the lungs. The "barrel chest" is a physical manifestation of this disease, as the chest wall becomes rounded and overly compliant due to trapped air and the abnormal lung expansion.

Patients with emphysema often experience chronic obstructive pulmonary disease (COPD), which contributes to persistent respiratory issues and decreased airflow capacity. The combination of these factors results in characteristic symptoms such as shortness of breath and a chronic cough.

The other conditions listed do not typically present with both a "barrel chest" and impaired lung function in the same manner. Pneumothorax involves the presence of air in the pleural space, which collapses part of the lung but does not result in a barrel chest. Asthma is characterized by episodes of airway constriction but does not typically cause a barrel chest unless chronic and severe. Interstitial lung disease involves scarring of lung tissue and stiffening of the lungs, which can lead to breathing difficulties but also does not commonly present