SN instructed patient in pulmonary fibrosis and in how it harms the tissues deep in the lungs. The air sacs in the lungs and their supporting structures become inflamed and scarred. If scarring progresses happen, then it makes your lungs thick and stiff. That makes it hard for the patient to catch their breath, and their blood may not get enough oxygen.
SN instructed patient in pulmonary fibrosis and that it means thickening of the lungs at the alveolar / capillary level, so it's harder for gas exchange to occur.