Idiopathic pulmonary fibrosis is scarring or thickening of the lungs without a known cause.

No one knows what causes pulmonary fibrosis or why some people get it. It causes the lungs to become scarred and stiffened. This stiffening may make it increasingly difficult to breathe. In some people the disease gets worse quickly (over months to a few years), but other people have little worsening of the disease over time.

The condition is believed to result from an inflammatory response to an unknown substance. "Idiopathic" means no cause can be found. The disease occurs most often in people between 50 and 70 years old.

• Chest pain (occasionally)
• Cough (usually dry)
• Decreased tolerance for activity
• Shortness of breath during activity (this symptom lasts for months or years, and over time may also occur when at rest)

The health care provider will perform a physical exam and ask questions about your medical history. Your doctor will ask whether you have been exposed to asbestos and if you have been a smoker.

Patients with idiopathic pulmonary fibrosis have abnormal breath sounds called crackles. Patients with advanced disease may have blue-colored skin (cyanosis) around the mouth or in the fingernails due to low oxygen.

Examination of the fingers and toes may show abnormal enlargement of the fingernail bases (clubbing).

Tests that help diagnose idiopathic pulmonary fibrosis include the following:

• Bronchoscopy with transbronchial lung biopsy
• Chest CT scan
• Chest x-ray
• Measurements of blood oxygen level
• Pulmonary function tests
• Surgical lung biopsy
• Tests for connective tissue diseases such as rheumatoid arthritis, lupus, or scleroderma

No known cure exists for idiopathic pulmonary fibrosis. Unfortunately, no medication has been shown to improve the outcome of patients with this condition.

• For some people, medications such as corticosteroids and cytotoxic drugs may help reduce swelling (inflammation).
• Ongoing clinical studies are experimenting with new treatments that have been shown to hep some people with idiopathic pulmonary fibrosis.
• Oxygen may be necessary in patients who have low blood oxygen levels.
• Lung rehabilitation will not cure the disease, but can help maintain exercise capacity (the ability to exercise without breathing difficulty).

Some patients with advanced pulmonary fibrosis may need a lung transplant.

You can ease the stress of illness by joining a support group where members share common experiences and problems.

See also: Lung disease - support group

Some patients may improve when they are treated with corticosteroids or cytotoxic drugs, but in most people the disease can get worse even with treatment. This worsening can happen quickly, or very slowly.

• Chronic hypoxemia (low blood oxygen level)
• Cor pulmonale
• Pneumothorax
• Polycythemia (abnormally high levels of red blood cells)
• Pulmonary hypertension
• Respiratory failure

Call for an appointment with your health care provider if you develop a regular cough or shortness of breath.

Avoiding smoking may help prevent this condition, but how to prevent the cause is not known.

American Thoracic Society (ATS) and European Respiratory Society (ERS). Idiopathic pulmonary fibrosis: diagnosis and treatment: international consensus statement. Am J Respir Crit Care Med. 2000; 161:646-664.

Noth I, Martinez FJ. Recent advances in idiopathic pulmonary fibrosis. Chest. 2007; 132(2).