What is a common finding in pulmonary fibrosis as indicated by PFT results?

In pulmonary fibrosis, a key characteristic of the disease is the restriction of lung expansion due to the scarring and stiffening of lung tissue, which is reflected in the pulmonary function test (PFT) results. The correct answer highlights decreased lung volumes, indicating that the total lung capacity and vital capacity are both often reduced in patients with this condition because of the fibrotic changes that limit the lungs' ability to expand fully.

Additionally, pulmonary fibrosis often leads to a reduction in diffusing capacity, specifically the diffusing capacity for carbon monoxide (DLCO). This decrease occurs because the fibrotic tissue affects the alveolar-capillary membrane, impairing gas exchange. Therefore, in patients with pulmonary fibrosis, PFT results typically show both reduced lung volumes and a lower diffusing capacity, confirming difficulties with both lung volume and gas transfer.

In contrast, the other options portray conditions that do not align with the typical PFT findings for pulmonary fibrosis, such as suggesting increased lung volumes or normal lung function, which would be inconsistent with the restrictive nature of this lung condition.