What type of lung disease is characterized by reduced airflow?

• A. Obstructive lung disease
• B. Restrictive lung disease
• C. Both obstructive and restrictive
• D. None of the above

Answer: (A)

Obstructive lung disease is characterized by reduced airflow primarily due to the narrowing or blockage of the airways, which impairs the ability to exhale air from the lungs. Conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchiectasis fall under this category. In obstructive lung disease, the key feature is that there is an increase in the resistance within the airways, leading to airflow limitation, particularly during expiration. This is reflected in pulmonary function tests that show a decreased forced expiratory volume in one second (FEV1) relative to forced vital capacity (FVC), indicating airflow obstruction.

In contrast, restrictive lung diseases involve a reduction in lung volume rather than airflow limitation. They typically result from conditions that cause stiffness in the lungs or the chest wall, leading to difficulty in lung expansion. For example, pulmonary fibrosis or neuromuscular diseases can restrict the lungs' ability to expand, thus reducing total lung capacity but not necessarily affecting airflow resistance as seen in obstructive diseases.

Overall, the defining feature of obstructive lung disease is the difficulty in expelling air, making it the correct answer in this context.