Interstitial Lung Disease

Interstitial Lung Disease is a general term for a group of diseases which are characterised by inflammation and scarring of lung tissue.

It mainly affects the thin tissue around blood vessels and the thin walls of the air sacs damaging these tissues in a way that decreases their ability to absorb oxygen from inhaled air. This causes symptoms of increasing shortness of breath There are many different types of ILD (more than 100 types).

However, each type of ILD behaves differently. While some are slowly progressing and some more rapid in their progression. Some respond well to certain anti-inflammatory drugs. The progression of each disease, response to medication etc varies from patient to patient as well. This is why it is important for patients to be under regular monitoring with a pulmonologist.

Frequently Asked Questions

As there are many different types of ILD, the causes of ILD are also many. ILDS can be classified according to the source of inflammation such as those associated with:

Connective Tissue Disorders – Autoimmune disorders like Rheumatoid Arthritis, Scleroderma can also cause ILD

Occupational Exposure – Asbestos, Silica and heavy metal exposure has been known to cause ILD Smoking Some ILDS such as Respiratory Bronchiolitis ILD are caused by exposure to tobacco smoke

Infections Scarring caused by chronic active infections

Medications-Some medications such as some cancer chemotherapy agents can cause ILD Radiation exposure to radiation radiation therapy can cause ILD during

Unknown Causes – Some types of ILD have no known cause. Idiopathic Pulmonary Fibrosis, sarcoidosis, Acute Interstitial Pneumonia, Nonspecific Interstititial Pneumonitis do not have any known cause Hormonal Influence Some ILDs are more commonly seen in young women pointing to some
hormonal influence as well.

The two most common symptoms are slowly progressing breathing difficulty. The shortness of breath initially is with exercise but can progress to being short of breath even with light activity. Patients will notice that they get tired easily while walking or climbing stairs. A persistent dry cough with minimal or no phlegm. Some patients experience generalised tiredness and poor sleep.

Fever, weight loss, body ache/joint pains may also be there.

After a detailed history and clinical examination, your doctor will prescribe certain tests.

Blood Tests An extensive blood work up is usually done in case of ILD to try and find the cause
and target treatment towards that. Imaging A Chest X-ray and a CT scan of the chest are done (High Resolution CT chest).A contrast dye is sometimes injected during the CT chest. Some ILDS have typical patterns on CT scan which help doctors to clinch the diagnosis and also identify the exact area of the lung affected.

Lung Function Tests – Complete lung function tests with spirometry, lung volumes and Diffusion capacity for carbon monoxide are done.
Arterial Blood Gas – This may be done to assess oxygen content in the blood and also assess for carbon dioxide levels.

Exercise Oximetry is done to evaluate need for home oxygen.

Bronchoscopy and Biopsy – This is the single most important test in the diagnosis of ILD. A flexible bronchoscope is used to perform an endoscopic examination of the airways and obtain small pieces of lung tissue which can be examined by pathologists. The CT scan guides where these biopsies will be taken from. The bronchoscopy also gives samples to test for any co-existing infections like tuberculosis. This information is vital to planning treatment with any anti-inflammatory medications.

Surgical Biopsy Some patients may require to undergo a surgical biopsy, usually this is done by a procedure called VATS (Video Assisted Thoracoscopic Surgery) where through small incisions, the specialist can take pieces of lung tissue for analysis

Echocardiogram – As there can be effects on the heart due to ILD, an Echocardiogram may also be done to assess heart function and certain pressures are monitored.

Depending on the cause of the ILD different treatment regimens may be prescribed.


The main types of medications used in ILD are those which suppress inflammatory reactions in the body. These include steroids or drugs which modify the body’s immune responses. There are other medications besides steroids which also target the body’s immune response. These are sometimes used in conjunction with steroids and sometimes by themselves.

Most of these medications do have some long term side effects. Therefore, your doctor will regularly monitor your progress and your response to the medications as well as repeat blood tests to make sure that there are no harmful side effects. There are also certain new medications developed which have shown some promise in improving the lung function and quality of life of patients with ILD. (e.g. Pirfenidone) However, it must be stressed that patients with ILD must be regularly monitored by a specialist trained in the care of ILDS.

Oxygen: Some patients may require home oxygen therapy
Pulmonary rehabilitation: Patients with chronic lung diseases benefit from specialized physical therapy.

Lung transplant

A healthy diet, keeping appointments for health check ups with your doctor and regular exercise are the basic health routines that ever patient must establish. All patients with ILD need to be careful to avoid infection, air pollution and keep updated with vaccines annually.

Since the progression of ILD varies from patient to patient, the impact on day to day life varies from patient to patient. Patient with relatively milder forms of ILD, with good response to medicines find little change from their normal lifestyle. People with moderate to severe ILD need to make some changes to minimize the impact on day to day life. Some will need to use Oxygen at home. Ground floor accommodation or elevator equipped buildings are preferable as patients find difficulty with stairs.

Physical therapists and occupational therapists can help patients make adjustments in their daily routines to avoid feeling tired and short of breath.

In some instances, certain types of ILD have been seen to occur in families. Not all ILDS show a familial predisposition

All patients with ILD should receive an annual vaccination for the Flu virus (combined vaccine for H1N1 as well). All adult patients with ILD should receive a vaccine for bacterial pneumoniaas well. This dose may be repeated if the patient is over 65 and has received the first dose more
than 5-6 years ago.