Interstitial lung disease (ILD) is caused by swelling and scarring of the air sacs (alveoli), and their supporting structures (the interstitium). This leads to reduced levels of oxygen in the blood.

The interstitial lung diseases can be broken down into two large groups:

Those that have no known cause (idiopathic ILD)
Those with an identifiable cause

One recent system further divides idiopathic ILD into the following three groups:

Idiopathic pulmonary fibrosis/usual interstitial pneumonitis (IPF/UIP)
Non-specific interstitial pneumonitis (NSIP)
Acute interstitial pneumonitis (AIP)

Causes

There are dozens of different causes of ILD. Many occupational substances can cause ILD, including:

Asbestos
Coal dust
Cotton dust
Sand (silica) dust

Persons who are heavily exposed to known causes of occupational lung disease in the workplace are usually routinely screened for lung disease. This can include coal miners, sand-blasters, ship workers, and others. Occasionally, bird keeping or bathing in hot tubs may cause some forms of ILD.

The following diseases can cause ILD:

Lupus
Rheumatoid arthritis
Sarcoidosis
Scleroderma

Certain medications (such as bleomycin, amiodarone, and methotrexate) may also cause ILD.

Cigarette smoking may increase the risk of developing some forms of ILD and may cause the disease to be more severe.

Symptoms

Abnormal enlargement of the base of the fingernails (clubbing)
Blue color of the lips, skin, or fingernails due to low blood oxygen levels (cyanosis)
Decreased tolerance for activity
Dry cough
Rapid breathing
Shortness of breath at rest or while active

Exams and Tests

The health care provider will perform a physical exam. Dry, crackling breath sounds may be heard when listening to the chest with a stethoscope. The health care provider may notice nasal flaring.

The following tests may be done:

Blood tests to check for connective tissue diseases
Bronchoscopy with biopsy
Chest x-ray
CT scan of the chest
Lung biopsy
Measurement of the blood oxygen level at rest or during exertion
Pulmonary function tests

Treatment

The treatment depends on the cause of the disease. Most often, anti-inflammatory drugs, such as corticosteroids or immunosuppressing drugs, are prescribed.

If there is no specific treatment for the condition, therapy is aimed at making the person more comfortable and supporting lung function. Those with low blood oxygen levels will receive oxygen. Lung rehabilitation can help people with advanced ILD.

Some patients with advanced ILD may need a lung transplant.

Outlook (Prognosis)

Chances of recovery or the disease getting worse depend on the cause, and how severe the disease was when it was first diagnosed.

Possible Complications

Hypoxemia
Pulmonary hypertension
Respiratory failure
Right sided heart failure (cor pulmonale)

When to Contact a Medical Professional

Call your health care provider if you have shortness of breath at rest that lasts for any period of time.

Prevention

Avoid exposure to substances known to cause lung disease.

Quitting smoking can prevent ILD from getting worse.

Interstitial lung disease is made up of group of disorders that affects the lungs. The presence of interstitial lung disease results to lung scarring which affects the ability to breathe properly.

Lung scarring found in interstitial diseases is most of the time irreversible though medications are used to slow down the damage to the lungs but patients will not get back the full capacity of their lungs.

Researches are being done to know the exact causes as well as the effective medicines for interstitial diseases as most of the cases of interstitial disease have developed gradually and without clear cause.

Symptoms of Interstitial Lung Disease

Interstitial lung disease covers different kinds of disorder that affects the lungs but with the variety of disorders, the most common symptoms are:

Presence of dry cough
Shortness of breath especially after strenuous activity

These symptoms are usually mistaken for other reasons like overweight or just common respiratory infection but unknowingly, the disease progresses and breathing becomes worse.

With the advancement of interstitial lung disease, you may experience that you're running out of breath even while you are just doing simple activities like eating or chatting over the phone.

Other symptoms may include wheezing, pain in the chest and clubbing of your fingers.

Risk Factors for Interstitial Lung Disease

Here are the factors that make a person more susceptible to Interstitial Lung Disease

Environmental pollutants
Age
Chemotherapy and radiation
Sex