Interstitial Lung Diseases

Interstitial lung diseases (ILDs) are a group of more than 200 different disorders that cause scarring in the lungs. Scar tissue in the lungs can make it harder for you to breathe normally.

In ILDs, scarring damages tissues in or around the lungs’ air sacs and airways. The lung interstitium is the space where the air sacs, called alveoli, come in contact with connective tissue and blood vessels to exchange oxygen and carbon dioxide. If you have an ILD, the interstitial tissue becomes thick and stiff, making it harder for oxygen to move out of the lungs and into the bloodstream and for carbon dioxide to move out of the bloodstream and into the lungs. Visit our How the Lungs Work Health Topic to learn more about what happens to the blood in the lungs.

ILDs may be caused by your genes, medicines, or other medical conditions such as sarcoidosis and certain autoimmune disorders. Exposures to substances in the environment can also lead to some types of ILDs, including asbestos-related lung diseases and hypersensitivity pneumonitis. For some ILDs, such as idiopathic pulmonary fibrosis, the cause of the scarring is unknown. Childhood ILDs can have the same or different causes as ILDs in adults.

signs and symptoms may include dry cough, shortness of breath, chest discomfort, and Fatigue. Pulmonologists and other doctors and nurses who specialize in lung disease may diagnose an ILD based on your medical and family histories and results from diagnostic tests and imaging procedures, including pulmonary function tests and a chest CT (computed tomography) scan.

ILDs can be mild or severe, and the amount of scarring can get worse over time. Depending on which ILD you have and how severe it is, your doctor may recommend avoiding environmental exposures if they trigger your condition. Alternatively, your doctor may recommend treating your condition and symptoms with medicines, pulmonary rehabilitation, oxygen therapy, or a lung transplant. Untreated ILDs can lead to complications such as growth problems in children, venous thromboembolism, lung cancer, pulmonary hypertension, heart failure, and respiratory failure.

Scarring in the lungs is often permanent, but early diagnosis and treatment can help slow or stop the scarring. Your medical team can help you learn how to manage your condition to improve your quality of life.

Visit Interstitial Lung Diseases for more information about this topic.

Research for Your Health

The NHLBI is part of the U.S. Department of Health and Human Services’ National Institutes of Health (NIH)—the Nation’s biomedical research agency that makes important scientific discovery to improve health and save lives. We are committed to advancing science and translating discoveries into clinical practice to promote the prevention and treatment of heart, lung, blood, and sleep disorders including interstitial lung diseases (ILDs). Learn about current and future NHLBI efforts to improve health through research and scientific discovery.

Improving health with current research
- Interstitial Lung Diseases

Learn about the following ways the NHLBI continues to translate current research into improved health for people who have an interstitial lung disease. Research on this topic is part of the NHLBI’s broader commitment to advancing scientific discovery on lung diseases.

  • The NHLBI Stimulates New Treatment Approaches for Lung Disease. The Centers for Advanced Diagnostics and Experimental Therapeutics in Lung Diseases (CADET) program stimulates the development of new treatments for lung diseases and sleep disorders. The first stage, CADET I, supported research on how lung diseases develop. The second stage, CADET II, is funding research on new drugs. For information on CADET research on ILDs, visit NHLBI Supports CADET Researchers to Produce New Pulmonary Disease Drugs.
  • Advancing the Understanding of Lung Development. The Molecular Atlas of Lung Development Program (LungMAP) is building a molecular map of the developing lungs in humans and mice. The program is helping advance lung research, in part through its Web-based data resource, called BREATH, that allows users to access LungMAP data and findings.
  • Supporting Research Collaboration. The Pulmonary Trials Cooperative brings together patients, researchers, and healthcare professionals from more than 50 institutions, with a common goal of developing new treatments and testing current clinical care practices for ILDs and other lung diseases.

Advancing research for improved health
- Interstitial Lung Diseases

In support of our mission, we are committed to advancing interstitial lung disease research in part through the following ways.

  • We perform research. Our Division of Intramural Research, which includes investigators from the Pulmonary Branch, performs research on interstitial lung diseases.
  • We fund research. The research we fund today will help improve our future health. Our Division of Lung Diseases oversees much of the research on interstitial lung diseases we fund, helping us understand and manage the conditions. Search the NIH RePORTer to learn about research the NHLBI is funding on interstitial lung diseases.
  • We stimulate high-impact research. Our Trans-Omics for Precision Medicine (TOPMed) program includes participants who have sarcoidosis or idiopathic pulmonary fibrosis, two types of ILDs, which may help us understand how genes contribute to differences in disease severity and how patients respond to treatment. The NHLBI Strategic Vision highlights ways we may support research over the next decade.

Participate in NHLBI Clinical Trials

We lead or sponsor many studies on interstitial lung diseases (ILDs). See whether you or someone you know is eligible to participate in our clinical trials.

Are you between 40 and 85 with worsening idiopathic pulmonary fibrosis?

This study aims to test a new combination treatment for acute exacerbations, a life-threatening complication of idiopathic pulmonary fibrosis (IPF) that has no approved treatment. The treatment is meant to help stop part of the immune system from further injuring the lung tissue. To participate in this study, you must be between 40 and 85 years old and have worsening IPF. This study is located in Birmingham, Alabama; Boston, Massachusetts; Philadelphia, Pennsylvania; and Pittsburgh, Pennsylvania.

Do you have systemic sclerosis?

This study aims to test the safety and effectiveness of a treatment in people who have the autoimmune disease systemic sclerosis. The treatment involves adding a medicine to the treatment of mycophenolate to test its ability to slow progression of lung fibrosis. To participate in this study, you must be at least 18 years old, have systemic sclerosis, and be at risk for progression of lung fibrosis. This study is located in Chicago, Illinois.

Do you have a first-degree relative diagnosed with an interstitial lung disease?

This study aims to better understand how interstitial lung diseases develop, by looking at the lungs of people who are at risk for an ILD. Participants will undergo a computed tomography (CT) scan, and researchers will look for visual evidence of the disease in an early stage. To participate in this study, you must be at least 35 years old and have a first-degree relative with a clinical diagnosis of ILD or be at least 50 years old with a smoking history of at least one pack of cigarettes per day. This study is located in New York, New York.

Are you an adult who has idiopathic pulmonary fibrosis or an advanced lung cancer?

This study aims to see whether a new imaging dye for positron emission tomography (PET) is effective at looking at fibrosis in lung cancer and idiopathic pulmonary fibrosis (IPF). Participants will be given the imaging dye and then receive a PET scan. To participate in this study, you must either be between 18 and 80 years old and have lung cancer or be a healthy volunteer or be between 50 and 80 years old and have IPF. This study is located in Boston, Massachusetts.

More Information

After reading our Interstitial Lung Diseases Health Topic, you may be interested in additional information found at the following resources.

Non-NHLBI resources
- Interstitial Lung Diseases


Dr. Adrienne Campbell-Washburn speaking at NHLBI’s Division of Lung Diseases 50th anniversary symposium
Research Feature
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