Pulmonary fibrosi is a condition in which tissue deep in your lungs becomes thick and stiff, or scarred, over time. The development of the scarred tissue is called fibrosis. As the lung tissue becomes thicker, your lungs lose their ability to move oxygen into your bloodstream. As a result, your brain and other organs don't get the oxygen they need.
In some cases, doctors can find out what's causing the fibrosis. But in most cases, they can't find a cause. They call these cases idiopathic pulmonary fibrosis (IPF). IPF is a serious condition. About 200,000 Americans have it. About 50,000 new cases are diagnosed each year. IPF mostly affects people who are 50 to 75 years of age. IPF varies from person to person. In some people, the lung tissue quickly becomes thick and stiff. In others, the process is much slower. In some people, the condition stays the same for years. IPF has no cure yet. Many people live only about 3 to 5 years after diagnosis. The most common cause of death related to IPF is respiratory failure.