Pulmonary Fibrosis is scarring in the lungs. Over time, the scar tissue can destroy the normal lung and make it hard for oxygen to get into your blood. Low oxygen levels (and the stiff scar tissue itself) can cause you to feel short of breath, particularly when walking and exercising. Pulmonary fibrosis isn’t just one disease. It is a family of more than 200 different lung diseases that all look very much alike. The PF family of lung diseases falls into an even larger group of diseases called the interstitial lung diseases (ILD), which includes all of the diseases that have inflammation and/or scarring in the lung. When an interstitial lung disease does include scar tissue in the lung, we call it pulmonary fibrosis.

IPF is a form of interstitial lung disease, primarily involving the interstitium (the tissue and space around the air sacs of the lungs), and not directly affecting the airways or blood vessels. There are many other kinds of interstitial lung disease that can also cause inflammation and/or fibrosis, and these are treated differently.