A patient with a restrictive lung disorder is MOST likely to have which diagnosis?

• A. Asthma
• B. Bronchiectasis
• C. Sarcoidosis
• D. Chronic bronchitis

Answer: (C)

Restrictive lung disease lowers total lung capacity and other lung volumes because the lungs or chest wall are stiff, making it hard to fully expand. Sarcoidosis fits this pattern because it often involves the lungs with interstitial granulomatous inflammation and potential fibrosis, which decreases lung compliance and produces a restrictive physiology. On tests you’d expect reduced TLC and FVC with a normal or high FEV1/FVC ratio, and DLCO may be reduced due to impaired gas exchange. By contrast, asthma, chronic bronchitis, and bronchiectasis primarily cause obstructive patterns with airflow limitation and a lower FEV1/FVC ratio, not a global reduction in lung volumes.