Respiratory Disease

Interstitial Lung Diseases (Pulmonary Fibrosis)

interstitial lung diseases?

Interstitial lung disease, or ILD, includes more than 180 chronic lung disorders, which may be:

chronic
nonmalignant (non-cancerous)
noninfectious

Interstitial lung diseases are named for the tissue between the air sacs of the lungs called the interstitium -- the tissue affected by fibrosis (scarring).

Interstitial lung diseases may also be called interstitial pulmonary fibrosis or pulmonary fibrosis.

The symptoms and course of these diseases may vary from person to person, but the common link between the many forms of ILD is that they all begin with an inflammation.

bronchiolitis - inflammation that involves the bronchioles (small airways)

alveolitis - inflammation that involves the alveoli (air sacs)

vasculitis - inflammation that involves the small blood vessels (capillaries)

More than 80 percent of interstitial lung diseases are diagnosed as pneumoconiosis, a drug-induced disease, or hypersensitivity pneumonitis. The other types are:

sarcoidosis
idiopathic pulmonary fibrosis
bronchiolitis obliterans
histiocytosis X
chronic eosinophilic pneumonia
collagen vascular disease
granulomatous vasculitis
Goodpasture's syndrome
pulmonary alveolar proteinosis

How does interstitial lung disease occur?

In interstitial lung disease, the lung is affected in three ways:

Lung tissue is damaged in some known or unknown way.
The walls of the air sacs in the lungs become inflamed.
Scarring (fibrosis) begins in the interstitium.

Fibrosis results in permanent loss of that tissue's ability to breathe and carry oxygen. Air sacs, as well as the lung tissue between and surrounding the air sacs, and the lung capillaries, are destroyed by the formation of scar tissue.

The diseases may run a gradual or rapid course. People with ILD may have varied symptoms -- from very mild to moderate to very severe. The condition may remain the same for long periods of time or it may change quickly. The course of ILDs is unpredictable. If they progress, the lung tissue thickens and becomes stiff. The work of breathing then becomes more difficult and demanding. Some of the diseases improve with medication if treated when inflammation occurs. Some people may need oxygen therapy as part of their treatment.

What are the symptoms of interstitial lung diseases?

The following are the most common symptoms for interstitial lung diseases; however, each person may experience symptoms differently. Symptoms may include:

shortness of breath, especially with exertion
fatigue and weakness
loss of appetite
loss of weight
dry cough that does not produce phlegm
discomfort in chest
labored breathing
hemorrhage in lungs

The symptoms of interstitial lung diseases may resemble other lung conditions or medical problems. Consult your doctor for a diagnosis.

What causes interstitial lung diseases?

The cause of interstitial lung disease is not known; however, a major contributing factor is thought to be inhaling environmental pollutants. Other contributing factors include:

sarcoidosis
certain drugs or medications
radiation
connective tissue or collagen diseases
family history

How are interstitial lung diseases diagnosed?

In addition to a complete medical history and physical examination, the doctor may also request the following tests:

pulmonary function tests - to determine characteristics and capabilities of the lungs

spirometry - to measure the amount of air that can be forced out

peak flow meter - to evaluate changes in breathing and response to medications

blood tests - to analyze the amount of carbon dioxide and oxygen in the blood

x-ray

computerized axial tomography (CAT) scan

bronchoscopy - to examine the lung using a long, narrow tube called a bronchoscope

bronchoalveolar lavage - to remove cells from lower respiratory tract to help identify inflammation and exclude certain causes

lung biopsy - to remove tissue from the lung for examination in the pathology laboratory

Treatment for interstitial lung diseases:

Specific treatment will be determined by your doctor(s) based on:

your age, overall health and medical history
extent of the disease
your tolerance for specific medications, procedures or therapies
expectations for the course of the disease
your opinion or preference

Treatments may include:

oral medications, including corticosteroids
influenza vaccine
pneumococcal pneumonia vaccine
oxygen therapy from portable tanks
lung transplantation

This page was last updated on: June 8, 2006.

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