Interstitial lung disease (ILD) is the term used to describe a diverse group of disorders found in the tissue between the air sacs of the lungs that lead to fibrosis, or scarring of the interstitium tissue. In interstitial lung disease, inflammation, scarring or fibrosis thickens the interstitium, making the lung thick and restricted from filling to their normal capacity and preventing oxygen from passing freely into the bloodstream .

ILD accounts for 15 percent of the cases seen by pulmonologists (lung specialists).

Symptoms
  • Shortness Of Breathe
  • Dry Cough
  • Chest Discomfort
  • Fatigue
  • Occasionally Weight Loss

In most cases, by the time the symptoms appear lung damage has already been done so it is important to see your doctor immediately. Severe cases that are left untreated can develop life-threatening complications including high blood pressure, heart or respiratory failure.

Causes

There are many known causes of interstitial lung disease. These can include:

  • Exposures in the home or workplace (such as parakeets or asbestos)
  • Connective tissue diseases (such as lupus, scleroderma, or rheumatoid arthritis)
  • Use of certain medications
  • Radiation exposure
  • Smoking

The evaluation begins with a physical exam, blood tests, a chest x-ray, a chest CT scan, and pulmonary function testing. If a diagnosis cannot be made using these tests, a lung biopsy is often necessary. Lung biopsies can be performed in two ways.

  • Bronchoscopy: A same-day procedure, during bronchoscopy a flexible tube (about the diameter of a pen) is inserted through a nostril and advanced into the tracheobronchial tree of the lungs. Small lung tissue samples can be removed during this procedure. The patient receives an anesthetic to maintain comfort during this procedure.
  • Surgical Biopsy: Some types of ILD are more amenable to diagnosis by bronchoscopy than others. For those diseases that are not easily diagnosed by bronchoscopy, a surgical lung biopsy may be necessary (See the figure for a comparison of healthy and diseased lung tissue).

Lastly, exercise testing (such as a cardiopulmonary exercise test and a six-minute walking test) will be performed to help gauge the severity of disease.