What group of diseases is characterized by pathological limitations of airflow in the airway?

Chronic obstructive pulmonary disease (COPD) is characterized by ongoing airflow limitation that is not fully reversible. This group of diseases, which includes emphysema and chronic bronchitis, typically results from long-term exposure to irritants that damage the lungs and airways, most commonly cigarette smoke. In patients with COPD, the airflow limitation is often progressive and associated with an abnormal inflammatory response of the lungs.

Key characteristics of COPD include difficulty exhaling all the air from the lungs, leading to a decrease in airflow, especially during physical exertion. This condition differs from asthma, where airflow obstruction is usually reversible either spontaneously or with treatment. Pneumonia, while it can cause temporary airflow limitations due to inflammation or fluid in the lungs, does not encompass the chronicity seen in COPD. Interstitial lung disease involves a variety of conditions affecting the lung interstitium, leading to difficulty in the exchange of gases but does not primarily feature airflow limitation in the same manner as COPD.

Overall, COPD's defining feature of pathological airflow limitations distinctly aligns it with the question's focus on chronic, progressive respiratory disease.