Decreased FEV1/FVC ratio is most consistent with which pulmonary condition?

Decreased FEV1/FVC ratio is most consistent with which pulmonary condition?

• A. Emphysema
• B. Chronic bronchitis
• C. Restrictive pulmonary disease
• D. Pulmonary emphysema and chronic bronchitis

Answer: (D)

A lower FEV1/FVC ratio points to an obstructive pattern of lung disease. In obstruction, expiration is impeded and FEV1 is reduced more than FVC, so the ratio drops. Emphysema and chronic bronchitis are both classic obstructive conditions; emphysema involves loss of elastic recoil and air trapping, while chronic bronchitis involves airway inflammation and mucus production that narrow the airways. Both mechanisms slow the rate of exhalation, lowering FEV1 relative to FVC. In restrictive diseases, FEV1 and FVC fall together, so the ratio is usually normal or even increased. Thus, the decreased ratio is most consistent with emphysema and chronic bronchitis together.

A lower FEV1/FVC ratio points to an obstructive pattern of lung disease. In obstruction, expiration is impeded and FEV1 is reduced more than FVC, so the ratio drops. Emphysema and chronic bronchitis are both classic obstructive conditions; emphysema involves loss of elastic recoil and air trapping, while chronic bronchitis involves airway inflammation and mucus production that narrow the airways. Both mechanisms slow the rate of exhalation, lowering FEV1 relative to FVC. In restrictive diseases, FEV1 and FVC fall together, so the ratio is usually normal or even increased. Thus, the decreased ratio is most consistent with emphysema and chronic bronchitis together.