Interstitial lung disease

What is interstitial lung disease?

Interstitial lung disease is the name used to describe a larger group of lung conditions. These conditions affect the interstitium, a network of lung tissue that supports the air sacs (called alveoli) that help you breathe.

Interstitial lung disease causes inflammation, scarring and thickening of the tissue around the air sacs. Other parts of the lungs can be affected, too. When the air sacs are scarred or damaged, they don’t work as well, causing breathing issues.

Types of interstitial lung disease

There are more than 200 types of interstitial lung disease. Some of these types include:

• Asbestosis – Inflammation and scarring on the lungs caused by breathing in asbestos.
• Bronchiolitis obliterans with organizing pneumonia (BOOP) – May also be referred to as cryptogenic organizing pneumonia (COP). Causes inflammation in the small airways (called bronchioles) and air sacs of the lungs.
• Desquamative interstitial pneumonitis – Inflammation in the lungs often caused by heavy smoking.
• Interstitial pneumonia – Occurs when certain bacteria, viruses or fungi infect the interstitium.
• Idiopathic pulmonary fibrosis – Occurs when scar tissue grows for an unknown reason in the interstitium.
• Sarcoidosis – Causes inflammation in the interstitium. It may also cause swollen lymph nodes and issues with your heart, skin, eyes and nerves.

Symptoms of interstitial lung disease

The most common symptom of interstitial lung disease is dyspnea, or shortness of breath. With most types of interstitial lung disease, shortness of breath develops slowly and can worsen over time.

Other symptoms may include:

• Difficulty breathing
• Discomfort in the chest
• Dry cough
• Fatigue and weakness
• Loss of appetite
• Unexplained weight loss

Because symptoms of interstitial lung disease can vary from person to person, and can be similar in other medical conditions, it’s important to see a doctor for proper diagnosis.

Causes of interstitial lung disease

In most cases, the exact cause of interstitial lung disease is unknown; however, having certain medical conditions, taking certain medications and even breathing in hazardous materials may increase your chances of developing it. These include:

• Autoimmune disorders that affect the lungs, such as rheumatoid arthritis, lupus or scleroderma.
• Certain antibiotics, heart medications, anti-inflammatory and chemotherapy drugs.
• Breathing in different toxins and pollutants such as dust, talc, asbestos, coal or mold.

Other risk factors may include:

• Age – It’s more likely to affect adults.
• Occupation – Those who work in mining, farming, construction or another field where there is exposure to certain toxins are at an increased risk.
• Smoking – Some forms of interstitial lung disease are more common among those who smoke. Smoking can also make the condition worse.
• Medical conditions – Those who have gastroesophageal reflux disease (GERD) may be at increased risk.
• Radiation treatments – Those who have undergone radiation treatments for cancer may have an increased risk.

Diagnosing interstitial lung disease

You may first see your doctor about shortness of breath or a dry cough you’re experiencing. If needed, they can refer you to a pulmonologist (lung doctor) who can help you get an accurate diagnosis and start treatment right away.

To diagnose interstitial lung disease, your doctor will do a physical exam, discuss your medical history and perform some tests. These tests may include:

• Spirometry – This lung function test allows your doctor to measure the amount of air you breathe in and out. During this test, you’ll be asked to take a deep breath in and blow into a mouthpiece connected to a small device. This device will test how fast you blow air out of your lungs.
• Chest X-ray – This allows your doctor to see the condition of your lungs and heart, and potentially rule out other causes of your symptoms.
• Chest CT (computed tomography) scan – This allows your doctor to get a more detailed look at your lungs. If your doctor suspects you have interstitial lung disease, they may take a higher-resolution CT scan to get an even better look at your interstitium.
• Lung biopsy – During a biopsy, your doctor will remove a small amount of tissue from your lungs to examine closely under a microscope. If possible, the biopsy can be collected through a minimally invasive procedure called a bronchoscopy, which involves placing a thin, flexible tube through your mouth or nose to your lungs.