Pulmonary fibrosis is a progressive disease that causes scarring of the lung tissue.

"The current thinking is that pulmonary fibrosis begins with repeated injury to the tissue within and between the tiny air sacs (alveoli) in your lungs. The damage eventually leads to scarring (fibrosis), which stiffens your lungs and makes breathing difficult. The most common symptoms are shortness of breath and a dry cough."

The symptoms of Pulmonary Fibrosis are: shortness of breath, a dry cough, fatigue, unexplained weight loss, and aching muscles and/or joints.  Many of the symptoms don't appear until the disease has progressed and irreversible damage has already occured. 

Hundreds of factors can cause lung damage.  Some examples are: occupational and environmental factors, radiation, medication, acid reflux, tuberculosis, and pneumonia.

Treatment for this condition currently are medication and therapy to improve lung function.  The most extreme form of treatment would be a lung transplant.