With emphysema does the FVC reduce or increase?

In emphysema, the Forced Vital Capacity (FVC) typically remains normal or may slightly decrease, but the key change is a reduction in the Forced Expiratory Volume in 1 second (FEV1). This results in a decreased FEV1/FVC ratio, indicating an obstructive pattern of lung disease. The primary issue in emphysema is the loss of elastic recoil in the lungs, leading to difficulties in exhaling air efficiently.