Which chronic lung disease includes chronic bronchitis and emphysema and is commonly caused by cigarette smoking?

• A. Cystic fibrosis
• B. Chronic obstructive pulmonary disease
• C. Pneumothorax
• D. Pneumonia

Answer: (B)

The main idea is recognizing COPD as the chronic lung disease that combines chronic bronchitis and emphysema, with cigarette smoking as the most common cause.

Chronic bronchitis involves a long-term productive cough due to mucus hypersecretion and airway inflammation, while emphysema involves destruction of the alveolar walls leading to loss of elastic recoil and air trapping. Together, they cause progressive airflow limitation and dyspnea, which is characteristic of COPD. Smoking provides the ongoing irritant exposure that drives these structural changes, making it the primary risk factor for COPD.

Cystic fibrosis is a genetic condition that also affects the lungs but originates from a mutation leading to thick mucus and infections, not primarily driven by smoking. Pneumothorax is an acute event where air accumulates in the pleural space, causing lung collapse rather than a chronic, progressive disease. Pneumonia is an acute infection causing lung consolidation, fever, and rapid onset symptoms, not a chronic, smoking-related airflow limitation.

So, the chronic, smoking-related disease that encompasses both chronic bronchitis and emphysema is COPD.