Which statement about obstructive lung disease is NOT true?

• A. It does not involve measurable airflow rates such as FVC, FEV1, FEV25-75, or PEFR
• B. It is characterized by reduced airflow rates
• C. Lung volumes are within normal range or larger
• D. It includes asthma, emphysema, chronic bronchitis, bronchiectasis

Answer: (D)

The key idea here is how obstructive lung disease presents on spirometry and in expiratory airflow. Obstructive conditions impair the ability to exhale quickly, so you see measurable changes in expiratory flow—most notably a reduced FEV1 and a reduced FEV1/FVC ratio. FVC can be normal or decreased depending on disease severity, but the important point is that airflow rates are indeed measurable and are diminished.

Therefore, saying that obstructive disease does not involve measurable airflow rates is incorrect. The other statements line up with typical features: airflow rates are reduced overall; lung volumes can be normal or increased due to air trapping and hyperinflation; and asthma, emphysema, chronic bronchitis are classic examples of obstructive processes (with bronchiectasis also often presenting with obstructive physiology).