Pulmonary fibrosis, or scarring of the lungs, may result from a variety of lung injuries or diseases termed interstitial lung disease, or ILD. ILD is a broad group of lung diseases that includes more than 130 disorders. It can affect both men and women alike. In ILD, the lungs become scarred, or fibrotic, causing them to be stiff and smaller in volume. A person with ILD can experience shortness of breath with exercise, and can have a dry cough. Some patients may also have fever, weight loss, fatigue, muscle and joint pain, and abnormal chest sounds, depending on the cause of the scarring. Rounding of the fingers, or clubbing, is one form of ILD. Some known causes include occupational and environmental exposure, drugs, poisons, and certain connective tissue diseases. Two-thirds of ILD cases have no known cause and are therefore termed idiopathic, meaning of unknown origin.

Making a diagnosis of ILD and finding out the cause are done with a thorough medical history, a complete exam, a chest x-ray, breathing tests, and measurements showing the blood oxygen level at rest and with exercise. A bronchoscopy is performed to check for any inflammatory cells involved. A surgical lung biopsy is usually needed to make a specific diagnosis and to determine the degree of inflammation and scarring present (to stage the disease.)

Two components are usually present -- inflammation and scarring. This process is similar to the way the body heals a cut. Early healing causes redness and inflammation, with many activated cells surrounding the area. Then a process of fibrosis or scarring occurs that prevents further damage; however, in the lungs, the elastic quality of the lung tissue is lost and tightening or stiffness results. Treatment is targeted at reducing the inflammation in the lungs and preventing further permanent scarring.

Research on ILD at the University of Michigan