No one knows what causes idiopathic 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 be due to an inflammatory response to an unknown substance or injury. "Idiopathic" means no cause can be found. The disease occurs most often in people between 50 and 70 years old.
Shortness of breath during activity (this symptom lasts for months or years, and over time may also occur when at rest)
Signs and tests
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:
Some patients may improve or stay stable for a long time when they are treated with corticosteroids or cytotoxic drugs. However, in most people the disease can get worse even with treatment. This worsening can happen quickly, or very slowly.
Call your health care provider if your breathing is:
Faster than before
Shallow, and you cannot get a deep breath
Also call your health care provider if:
You need to lean forward when sitting to breathe comfortably.
You are using muscles around your ribs to help you breathe.
You are having headaches more often.
You feel sleepy or confused.
You have a fever.
You are coughing up dark mucus.
Your fingertips, or the skin around your fingernails is blue.
American Thoracic Society (ATS), European Respiratory Society (ERS), Japanese Respiratory Society (JRS), and Latin American Thoracic Association (ALAT). Idiopathic pulmonary fibrosis: evidence based guideline for diagnosis and management. Am J Respir Crit Care Med. 2011; 183:788-824.
Selman M, Morrison LD, Noble PW, King TE Jr. Idiopathic interstitial pneumonias. In: Mason RJ, Broaddus VC, Martin TR, et al, eds. Murray and Nadel's Textbook of Respiratory Medicine. 5th ed. Philadelphia, Pa: Saunders Elsevier; 2010:chap 57.
David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Denis Hadjiliadis, MD, Assistant Professor of Medicine, Division of Pulmonary, Allergy and Critical Care, University of Pennsylvania, Philadelphia, PA. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M. Health Solutions, Ebix, Inc.