Causes

Idiopathic means the cause is not known.

Researchers think that IPF is an exaggerated and uncontrolled inflammatory response. This produces the scar tissue. What starts the cycle is not known. Over time, scarring surrounds the thin walled air sacs in the lungs. This makes the tissue thicker and stiffer. As a result, breathing becomes difficult. The lungs gradually lose their ability to pass oxygen to the rest of the body.

Healthy Alveoli

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Risk Factors

Although the cause of IPF is not known, the factors below may increase the risk of getting it:

• Sex: male
• Age: 50 and older
• Cigarette smoking
• Viral infection
• Occupational exposures to dusts containing silica, bacteria, and animal proteins or to gases and fumes
• Medications such as nitrofurantoin , sulfasalazine , amiodarone , propranolol , methotrexate , cyclophosphamide , bleomycin
• Gastroesophageal reflux disease (GERD)
• Other family members with IPF