“Pulmonary fibrosis is scarring in your lungs. It can make it hard to expand your lungs and get enough oxygen to your body. It can be idiopathic (without a known cause) or result from autoimmune diseases, environmental factors or medications. Pulmonary fibrosis usually gets worse over time, but how quickly it gets worse is different for everyone.

 You might also be at a higher risk for pulmonary fibrosis if you:

• Are 65 or older
• Are male
• Have a family member with pulmonary fibrosis
• Have certain conditions caused by changes in your DNA, like dyskeratosis congenita (a rare type of bone marrow failure)”

Cleveland Clinic (Pulmonary Fibrosis: Causes, Symptoms & Treatment)