Interstitial Lung Disease

Interstitial lung disease (ILD) is a term for a group of conditions that cause inflammation and scarring in your lungs. Symptoms of ILD include shortness of breath and a dry cough. ILD can be caused by medication, radiation therapy, connective tissue diseases or inhaling harmful substances. Lung damage caused by ILD is often irreversible.


Symptoms of interstitial lung disease include shortness of breath, cough, fatigue and chest discomfort.
The most common symptoms of interstitial lung disease are shortness of breath and dry cough, but you may have other symptoms depending on the cause.

What is interstitial lung disease?

Interstitial lung disease (ILD) is a term for a group of over 200 conditions that cause inflammation and scarring in your lungs. ILD damages the tissues between the small air sacs in your lungs (alveoli) and the blood vessels around them. This makes it harder for you to move oxygen out of your lungs and into your body.

Interstitial lung disease is also called diffuse parenchymal lung disease (DPLD).


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What happens when you have interstitial lung disease?

When you have interstitial lung disease, parts of your lungs that help oxygen get into your blood and out to your tissues are damaged. Scarring in your lungs makes it hard to breathe, and you might have a chronic cough. Lack of oxygen can make you feel tired all the time.

When damage continues to get worse, you can have life-threatening complications, like lung infections and respiratory failure (not enough oxygen or too much carbon dioxide in your body).

What are examples of interstitial lung disease?

There are over 200 interstitial lung diseases. The most common is idiopathic pulmonary fibrosis, followed by diseases caused by occupational exposures or connective tissue disorders. A few other examples include:

What’s the difference between interstitial lung disease and pulmonary fibrosis?

Pulmonary fibrosis is a type of interstitial lung disease. Not all ILD is pulmonary fibrosis.


Who is most at risk for interstitial lung disease?

You’re more likely to develop interstitial lung disease if you:

  • Are over 70.
  • Were assigned male at birth.
  • Smoke or used to smoke.
  • Have a history of certain illnesses or conditions, like hepatitis C, tuberculosis, pneumonia, COPD or connective tissue disease.
  • Work around substances that can irritate your lungs, like asbestos, silica, molds, fungi or bacteria.
  • Have had chest radiation.

How serious is interstitial lung disease?

Since there are many kinds of interstitial lung diseases, any one case could be mild or very serious. Most kinds of ILD cause irreversible lung damage. The most serious ILDs are progressive, where your condition continues to worsen over time.


Symptoms and Causes

What are the symptoms of interstitial lung disease?

Common symptom of interstitial lung disease include:

Symptoms are usually mild at first but get worse over months or years. You may have additional symptoms depending on the underlying cause of ILD.

What causes interstitial lung disease?

The causes of interstitial lung disease are usually described as known or unknown. A known cause is when ILD happens because of a disease you’re living with or something you were exposed to, like certain medications, radiation or harmful substances.

An unknown cause (idiopathic) is when you have ILD but you don’t have an underlying condition and haven’t been exposed to anything to cause it.

Known causes of interstitial lung disease

Known causes of interstitial lung disease include:

Unknown causes of interstitial lung disease

When your healthcare provider can’t find the cause of interstitial lung disease, it’s called idiopathic interstitial pneumonia. There are many types of idiopathic interstitial pneumonias. The most common ILD with an unknown cause is idiopathic pulmonary fibrosis.

Diagnosis and Tests

How is interstitial lung disease diagnosed?

Your healthcare provider will diagnose interstitial lung disease by doing a physical exam, getting imaging of your lungs and testing your lung function. During your exam, they’ll listen to your lungs for any unusual sounds that tell them your lungs aren’t working right. They’ll ask you about:

  • Your medical history and any ongoing conditions.
  • Medications you’re taking or have taken in the past.
  • Whether anyone in your family has certain conditions or connective tissue diseases.
  • If your work or hobbies expose you to certain causes of ILD.

What tests will be done to diagnose interstitial lung disease?

Tests your provider may perform to diagnose interstitial lung disease include:

  • Pulmonary function tests. Pulmonary function tests are usually breathing tests, but they can also be blood tests or exercise tests. They check how well your lungs are working.
  • Imaging tests. X-rays or high-resolution CT scans can be used to get pictures of your lungs.
  • Blood tests. Your provider will test a sample of your blood, taken from your arm, for signs of known causes of ILD.
  • Bronchoscopy. Your provider will insert a thin tube (bronchoscope) through your nose or mouth into your lungs to look at your airways.
  • Biopsy. Your provider will remove a small sample of tissue from your lung and study it under a microscope to help identify the type of ILD.

Management and Treatment

How is interstitial lung disease treated?

There’s no cure for interstitial lung disease. Treatment for ILD usually focuses on treating underlying disease and improving your symptoms. Your healthcare provider might prescribe physical therapy, supplemental oxygen or medication to reduce inflammation or slow down the disease.

What medications and treatments are used in interstitial lung disease?

  • Corticosteroids. Drugs like prednisone can help reduce inflammation.
  • Anti-fibrotic and cytotoxic drugs. These medications can slow down lung scarring. They include azathioprine, cyclophosphamide, pirfenidone and nintedanib.
  • Biologic drugs. Medications like rituximab are sometimes used to treat autoimmune diseases and other causes of ILD.
  • Treatment for GERD. Gastroesophageal reflux disease (GERD) can make ILD worse, so your provider may prescribe medications to keep stomach acid down.
  • Pulmonary rehabilitation. Breathing exercises and physical therapy can make your lungs stronger and breathing easier.
  • Oxygen therapy. Your provider will prescribe extra oxygen if you don’t have enough getting to your blood or tissues. It’s delivered through a mask or tube in your nose.
  • Lung transplant. Some people with severe cases of ILD get a lung transplant.

Side effects of treatment

Some treatments for interstitial lung disease can weaken your immune system. Your provider will monitor you closely for complications if you’re taking one of these medications.


How can I prevent interstitial lung disease?

Many causes of interstitial lung disease aren’t preventable. You can reduce your risk of ILD by managing underlying conditions and avoiding breathing in harmful substances.

  • Avoid or wear a respirator (a mask that filters particles from the air) when working around harmful substances, such as asbestos, metal dusts or chemicals.
  • Avoid or wear a respirator when working around things that can cause chronic allergic reactions, like hay, grain, bird droppings or feathers and heating and cooling systems.
  • If you have a connective tissue disease or sarcoidosis, talk to your healthcare provider about ways to manage your illness to prevent ILD.
  • Don’t smoke or quit smoking.

Outlook / Prognosis

What can I expect if I have interstitial lung disease?

How you and your healthcare provider manage interstitial lung disease depends on the cause. If you have an occupational exposure or allergy (hypersensitivity pneumonitis), you may have to stop working with whatever’s causing your ILD or take extra precautions.

While medications can help bring down inflammation, scarring caused by interstitial lung disease is permanent. If you have an underlying disease, management of it might help prevent further damage. If the cause is unknown, your healthcare provider will treat your symptoms and try to prevent more damage.

What are the complications of interstitial lung disease?

In severe cases of interstitial lung disease, you can have life-threatening complications, including:

What is the life expectancy of a person with interstitial lung disease?

The life expectancy for interstitial lung disease depends on the cause and severity. Some people with mild ILD can live normal lives without treatment or with minimal treatment. Your outlook (prognosis) is better if your disease isn’t getting worse (it’s stable).

For people with the most severe and rapidly worsening forms of interstitial lung disease, life expectancy is around 3-5 years after diagnosis.

Living With

How do I take care of myself with interstitial lung disease?

If you’ve been diagnosed with interstitial lung disease, the best way to take care of yourself is to make a plan with your healthcare provider to manage your symptoms and prevent further damage.

Treat any underlying conditions, and manage anything that could contribute to ILD (like GERD). If you work with substances that can damage your lungs or cause an ongoing allergic reaction, you may need to take special precautions.

When should I see my healthcare provider?

See your healthcare provider if you’ve had increasing shortness of breath, shortness of breath with exercise or an ongoing dry cough. The outlook for interstitial lung disease is best if treated as soon as possible.

What questions should I ask my healthcare provider?

  • What’s causing my disease?
  • What are my treatment options?
  • Will it get worse?
  • Can the damage be slowed down?
  • What changes can I make to improve my quality of life?

A note from Cleveland Clinic

There are dozens of types of interstitial lung disease. Some cases are mild, and some are very serious. You might find some scary statistics online, but only your healthcare provider can tell you what to expect in your specific case. Having honest conversations with your provider can help set your expectations. Together, you can make a plan to improve your symptoms and have the best quality of life.

Medically Reviewed

Last reviewed on 08/05/2022.

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