Which spirometry pattern characterizes restrictive lung disease?

Which spirometry pattern characterizes restrictive lung disease?

• A. Reduced FEV1/FVC ratio with normal or increased TLC
• B. Increased DLCO
• C. Obstructive pattern
• D. Reduced TLC with preserved FEV1/FVC

Answer: (D)

Restrictive lung disease limits how much the lungs can expand, so total lung capacity (TLC) is reduced. On spirometry, FEV1 and FVC decline, but they do so proportionally, leaving the FEV1/FVC ratio normal or even increased. This combination—reduced TLC with a preserved FEV1/FVC ratio—best characterizes restrictive disease. Obstructive patterns show a reduced ratio, and an increased DLCO is not typical for restrictive disease.

Restrictive lung disease limits how much the lungs can expand, so total lung capacity (TLC) is reduced. On spirometry, FEV1 and FVC decline, but they do so proportionally, leaving the FEV1/FVC ratio normal or even increased. This combination—reduced TLC with a preserved FEV1/FVC ratio—best characterizes restrictive disease. Obstructive patterns show a reduced ratio, and an increased DLCO is not typical for restrictive disease.