How does chronic bronchitis differ from emphysema?

Chronic bronchitis is distinguished primarily by inflammation of the bronchi, leading to a persistent cough and increased mucus production. This condition is marked by the production of phlegm on most days, which is a result of chronic irritation often due to smoking or long-term exposure to respiratory irritants. The hallmark of chronic bronchitis is the cough that lasts for at least three months in two consecutive years, attributable to the accumulation of mucus that obstructs airflow.

In contrast, emphysema is characterized by the destruction of alveoli, which are the small air sacs in the lungs where gas exchange occurs. This destruction leads to loss of lung elasticity and an abnormal enlargement of the air spaces, resulting in difficult exhalation and reduced oxygen uptake. While both conditions fall under the umbrella of chronic obstructive pulmonary disease (COPD), they affect different structures in the respiratory system and lead to different symptoms.

Understanding this distinction is critical, particularly for recognizing the specific symptoms each condition presents and their implications for treatment. Thus, the prominence of persistent cough and mucus production uniquely identifies chronic bronchitis, making it the correct choice in differentiating it from emphysema.