Pulmonary fibrosis is a thickening of the tissue of the lungs that can occur for a number of reasons. Repeated exposure to contaminants such as asbestos can result in the scarring of these delicate lung tissues. Some illnesses, like sarcoidosis and pneumonia, can cause this condition, and in some cases a medical treatment administered for another illness can damage the lung tissues. Regardless of the causes of pulmonary fibrosis, the condition may be chronic or little more than a mild discomfort that gets no worse over time.
When exposure to a hazardous chemical or substance is part of an individual's job, he or she can run the risk of developing this condition from repeated inhalation of dangerous pollutants. Asbestos is one of the most dangerous chemicals and was once one of the major causes of pulmonary fibrosis. The fumes from other liquid chemicals can start a similar process within the respiratory system. Dusty, dirty air can contain contaminants that the mucous layers of the respiratory system cannot remove entirely, which can then irritate the lining of the lungs. Cigarette smoke from direct inhalation or second-hand smoke can also encourage development of scar tissue in the lungs.
Other illnesses can be one of the causes of pulmonary fibrosis, as this condition can develop alongside another. Severe cases of pneumonia and tuberculosis can damage the lining of the lungs. Sarcoidosis, which is characterized by the swelling of tissues in one of a number of organs, can permanently create scar tissue when the condition occurs in the lungs and respiratory system. In some cases, acid reflux disease can also cause damage to the lungs that can lead to pulmonary fibrosis.
When radiation and chemotherapy treatments are given for conditions like cancer, pulmonary fibrosis can be a serious side effect of the medication. An individual taking some antibiotics, anti-depressants, or other mood-altering medications may develop the condition, as long-term use of some medications is among the causes of pulmonary fibrosis. In some cases, a medication does not have to be inhaled or in direct contact with the lungs in order to irritate the tissues. Similarly, some illnesses that develop in other parts of the body can still negatively impact the lungs. Rheumatoid arthritis has been linked to the development of scarring and stiffening of the lung tissues, as some causes of pulmonary fibrosis are linked to other conditions.
Some individuals develop pulmonary fibrosis with no identifiable cause. This condition is called idiopathic pulmonary fibrosis, and is thought to be brought on by a hereditary or environmental factor. The severity of this type of illness varies by the individual, who may end up getting no worse over time or developing difficulty breathing, chest pains, and difficulty performing tasks that require a high level of activity.