Question

When the values of FEV1 = 1.3 and FVC = 3.9, which of the following does this signify?

• A. Normal lung function
• B. Obstructive lung disease
• C. Restrictive lung disease
• D. Both

Hint:

Compute FEV1/FVC and compare it with the normal 0.7-0.8 cut-off.

Answer 1

The Correct Option is B

Step 1: The key spirometric number is FEV1 divided by FVC, which tells how fast air can be pushed out compared with the total volume exhaled.
Step 2: Plugging in the values gives $\frac{1.3}{3.9} = 0.33$, far under the healthy threshold of roughly 0.7.
Step 3: When this ratio drops, the airways are narrowed and emptying is slowed - the hallmark of obstruction such as COPD or asthma.
Step 4: In restriction the lungs are small but empty briskly, so the ratio is preserved or raised; a normal lung sits near 0.8. Neither fits a value of 0.33, leaving obstructive disease as the only match.
\[\boxed{\text{Obstructive lung disease}}\]