Interstitial lung disease risk factors: who is more likely to get it

What interstitial lung diseases are

Interstitial lung diseases are a group of several disorders that can cause scarring in your lungs. The scar tissue makes it harder for your lungs to carry oxygen and can make it harder to breathe normally (NHLBI). MedlinePlus describes them as a large group of diseases that inflame or scar the lungs, and calls the scarring pulmonary fibrosis (MedlinePlus).

In an ILD, the lung interstitium, the space between the air sacs and the small blood vessels around them, becomes thick and stiff. That makes it harder for oxygen to move into the blood and for carbon dioxide to move out. NHLBI says about 3 out of every 10,000 people in the United States are diagnosed with an ILD every year, and ILDs can be mild, serious or even life-threatening (NHLBI).

What causes them

NHLBI says ILDs are caused by damage to your lungs from things in your environment, your lifestyle habits or another health condition. Normally the body repairs lung injury, but in an ILD the healing process stops working correctly over time and the lungs may be repaired with scar tissue (NHLBI). Some types have no known cause, including the most common type, idiopathic pulmonary fibrosis (IPF) (NHLBI). MedlinePlus also says some types have no known cause (MedlinePlus).

Risk factors

NHLBI says many things can damage your lungs and raise your risk of an ILD. It lists (NHLBI):

• Family history: you have a higher risk if a close relative has an ILD. Changes in your genes can make you more likely to develop scar tissue in your lungs.
• Environment and occupation: exposure to mold, chemicals or bacteria at work or in your environment can damage your lungs. Breathing in dust from mining and construction work over a long time can raise your risk of asbestos-related lung disease, a type of ILD.
• Lifestyle habits: smoking can damage your lungs or make lung damage worse.
• Medicines: while rare, some antibiotics, heart medicines and chemotherapy drugs can raise your risk.
• Other health conditions: conditions such as sarcoidosis, autoimmune diseases, connective tissue disorders and viral infections such as COVID-19 can damage your lungs.
• Sex: some ILDs are more common in men or in women. IPF is more common, and causes more serious symptoms, in men. Lymphangioleiomyomatosis (LAM) is more common in women. Some autoimmune diseases and connective tissue disorders that cause ILDs are also more common in women.

NHLBI suggests telling your doctor if you think you may have been exposed to asbestos, so they can watch for symptoms or complications and start treatment early (NHLBI).

Dust and other particles

MedlinePlus says breathing in dust or other particles in the air is responsible for some types of ILD. The types it names are (MedlinePlus):

• black lung disease among coal miners, from inhaling coal dust
• farmer's lung, from inhaling farm dust
• asbestosis, from inhaling asbestos fibers
• siderosis, from inhaling iron from mines or welding fumes
• silicosis, from inhaling silica dust

It names autoimmune diseases and work exposure to molds, gases or fumes as other causes (MedlinePlus).

Symptoms

Symptoms depend on the type of ILD and how serious it is. They can come on quickly or slowly and get worse over time, and some people have no symptoms at first (NHLBI). NHLBI lists (NHLBI):

• shortness of breath
• a dry cough
• abnormal sounds when you breathe
• chest pain and discomfort
• extreme tiredness
• clubbing, a widening and rounding at the ends of the fingers or toes with a downward slope of the nails

Symptoms in children can be different from symptoms in adults (NHLBI).

How ILDs are found

NHLBI says your provider diagnoses an ILD from your symptoms, your medical and family histories, your risk factors and the results of tests. You may need to see a pulmonologist, a doctor who specializes in lung diseases. Common tests are blood tests, to look for an infection or autoimmune disease that can cause an ILD, and lung tests such as chest X-rays, CT scans and lung function tests. Sometimes a bronchoalveolar lavage (lung fluid sample) or a lung biopsy is needed (NHLBI). Genetic testing can also be part of the diagnosis (NHLBI).

Treatment and complications

Treatment depends on the cause and how serious the symptoms are. It does not cure the lung damage, but it can keep the damage from getting worse and help you breathe easier (NHLBI). If your ILD is caused by substances at work or in your environment, you will need to avoid them, and if you smoke, your doctor will ask you to stop. Depending on the type, treatment can include medicines (bronchodilators, corticosteroids or antifibrotics), oxygen therapy, pulmonary rehabilitation or, for severe disease that does not respond to other treatments, a lung transplant (NHLBI). MedlinePlus says treatment depends on the type of exposure and the stage of the disease (MedlinePlus).

Without treatment, NHLBI says ILDs may cause complications such as a collapsed lung, frequent lung infections, pulmonary hypertension, problems growing in children, lung cancer, respiratory failure, right-sided heart failure and blood clots (deep vein thrombosis and pulmonary embolism). Following your treatment plan can help prevent these problems (NHLBI). NHLBI also suggests routine follow-up care and pneumococcal, flu and COVID-19 vaccines to help prevent lung infections that can lead to more lung damage (NHLBI).

Can you prevent an ILD?

NHLBI says there is no way to prevent ILDs that are caused by your genes. You can prevent some ILDs by quitting smoking and avoiding substances at work or in your environment that can damage your lungs (NHLBI).

Common questions

Is an ILD the same as COPD, sarcoidosis or pulmonary hypertension?

No. ILDs are a group of disorders that scar the tissue in and around the lungs' air sacs (NHLBI). COPD is a separate group of lung diseases with its own guide here. Sarcoidosis is one of the conditions that can damage the lungs and raise the risk of an ILD (NHLBI), and pulmonary hypertension can be a complication of an ILD (NHLBI).

Do ILDs run in families?

Some can. You have a higher risk if a close relative has an ILD, and NHLBI says there is no way to prevent ILDs that are caused by your genes (NHLBI).

Can my job raise my risk?

It can. Exposure to mold, chemicals or bacteria at work can damage the lungs, and long-term dust exposure in mining and construction can raise the risk of asbestos-related lung disease (NHLBI). MedlinePlus names coal dust, farm dust, asbestos fibers, iron from mines or welding fumes, and silica dust (MedlinePlus).