Fast facts

  • Interstitial lung disease (ILD) is the name for a large group of  conditions in which lung scarring leads to breathing problems.
  • Risk factors for ILD are increasing age, exposure to lung irritants, and smoking.
  • The main symptoms of interstitial lung disease are shortness of breath and a dry cough.
  • Once lung tissue is damaged by ILD, the damage cannot be reversed, but treatment can help to manage symptoms and, in some cases, slow the progress of the condition.

What is interstitial lung disease?

Interstitial lung disease (ILD) is a term that covers a large group of medical conditions in which scarring of the lungs leads to long-term breathing problems.

Lungs

The pair of organs in the chest responsible for breathing.

Causes

The lungs are sponge-like organs, containing branching airways and millions of tiny air sacs called alveoli. The walls of the alveoli are made up of delicate connective tissue that allows oxygen to travel from air breathed into the lungs into the blood vessels, so it can be transported around the body.

In interstitial lung disease, the tissues of the lungs become scarred and damaged (a state known as fibrosis). It may be due to an abnormal healing response in the lungs.

The scarring reduces the ability of your lungs to expand to take in air and to transport oxygen into the bloodstream. As more of the lung tissue is affected, it becomes more difficult for the body to get the oxygen it needs.

When the cause of the scarring is not known, it is known as idiopathic pulmonary fibrosis. This is the most common form of ILD in older people.

There are also many other causes of ILD. These can include:

Allergens

An environmental substance that, although not harmful in itself, elicits a vigorous reaction from the immune system.

Bloodstream

The flow of blood within the blood vessels of the circulatory system.

Langerhans cell histiocytosis

A disorder of the immune system in which excess Langerhans cells (immune cells that display antigens on the cell surface) are produced.

Epstein-Barr virus

A virus of the herpes family that causes mononucleosis, also known as mono or glandular fever. It is also implicated in some other medical conditions.

Idiopathic

Without a known cause.

Lungs

The pair of organs in the chest responsible for breathing.

Neurofibromatosis

An inherited condition in which neurofibromas (benign tumours) form from the layer that encloses nerve fibres (sometimes called nerve fibre sheaths).

Pulmonary fibrosis

A respiratory disease in which scar tissue forms in the lung tissues, sometimes as a result of other lung diseases.

Radiation

Energy that is emitted, such as heat, light, or energy in electromagnetic waves. Different types of radiation can be used to diagnose and treat disease.

Sarcoidosis

An inflammatory condition that can affect the organs of the body, particularly the lungs, skin, liver and eyes.

Scleroderma

A rare condition in which excess collagen fibres are produced by the body, affecting the skin and internal organs.

Spores

A tiny single cell that is able to grow into an organism. Spores are produced by some plants and microorganisms, such as fungi.

Tuberous sclerosis

A rare genetic disease that causes tumours to grow in the brain and other organs and causes a combination of symptoms that may include seizures, intellectual disability, behavioural problems, and kidney disease.

Lymphangioleiomyomatosis

A lung disease that causes abnormal growth of the lung tissue, which can lead to breathing problems.

Risk factors

Factors that can increase the risk of developing interstitial lung disease include:

  • Age: although ILD can occur at any age, people are more likely to develop it as they get older;
  • Working in occupations in which there is increased exposure to pollutants and dusts, and;
  • Smoking.

Signs and symptoms

The two main symptoms of interstitial lung disease are:

  • Shortness of breath, particularly with physical activity, and;
  • A dry cough.

Chest pain or wheezing are uncommon symptoms, but can occur with some types of ILD.

Symptoms of ILD tend to develop gradually, and early on they may be mistaken for just getting older, or being out of shape. If you suspect you have problems with your lungs or breathing, it is important that you have it checked out, since early treatment can help to slow down the damage to the lungs caused by ILD.

Lungs

The pair of organs in the chest responsible for breathing.

Wheezing

Breathing with a whistling or rattling sound in the chest.

Methods for diagnosis

Diagnosing interstitial lung disease is not always straightforward because:

It is important for your doctor to identify the condition causing the symptoms because treatments and prognosis can vary. For this reason, your doctor may need to ask you questions about your medical history and your life to help identify what could be causing your symptoms.

Lung function testing

To assess how ILD affects your breathing, your doctor will generally recommend tests to measure lung function, which can include:

  • Spirometry, which measures how much air you can breathe in and out, and how fast you can breathe;
  • Diffusion capacity, which measures how well gases pass from your breath through your lungs into your bloodstream
  • Oximetry (measurement of arterial blood gases), which can indicate the levels of oxygen in your blood, and;
  • An exercise stress test. During this test you perform physical activity, such as riding an exercise bike or walking on a treadmill, while your lung function is monitored.

Other tests that may be used to help diagnose ILD include:

  • A chest X-ray or computerised tomography (CT) scans. The pattern of damage to the lung tissue can vary depending on the cause of the condition. These tests may also be used to monitor how your condition progresses;
  • Blood tests to check for autoimmune diseases, and;
  • Lung tissue samples. Small samples of tissue may be taken via bronchoscopy, in which a thin tube is passed through the mouth or nose and down the windpipe into the lungs. Alternatively, a surgical lung biopsy, in which samples are removed under general anaesthetic, may be recommended.

Autoimmune diseases

A medical condition in which the body's immune system abnormally targets substances that are normally found within the body.

Blood tests

During a blood test, blood can be drawn using a needle or by a finger prick. Your blood can then be analysed to help diagnose and monitor a wide range of health conditions.

Bloodstream

The flow of blood within the blood vessels of the circulatory system.

Computerised tomography

A scan that uses X-rays to create a 3D image of the body. This can detect abnormalities more effectively than a simple X-ray can.

General anaesthetic

An anaesthetic given to a person to put them to sleep while having an operation or medical procedure. Afterwards, the person regains consciousness and usually has no memory of the procedure. A general anaesthetic is given in hospital by a specialist called an anaesthetist.

Lungs

The pair of organs in the chest responsible for breathing.

X-ray

A scan that uses ionising radiation beams to create an image of the body’s internal structures.

Types of treatment

Your doctor may recommend:

  • Treatment for any underlying medical causes of interstitial lung disease, such as heartburn;
  • Stopping any medications that may have caused damage to your lungs, or;
  • Stopping or limiting exposure to any pollutants or allergens that may have caused damage to your lungs.

Unfortunately, once lung tissue has been damaged, there is no current treatment that can restore it. Treatments for ILD vary, depending on the cause, and aim to:

  • Slow the progression of the condition;
  • Improve symptoms, and;
  • Help to you to maintain your quality of life as much as possible.

Pulmonary rehabilitation

Pulmonary rehabilitation is a type of therapy specifically designed for people with chronic lung conditions who suffer from short breath. A health professional - usually a physiotherapist, exercise physiologist or nurse - will teach you exercises and techniques to help you learn how to maximise your quality of life.

Pulmonary rehabilitation includes:

  • Regular, safe physical activity and exercises to promote physical fitness;
  • Breathing techniques to help manage breathlessness;
  • Information on ways to conserve energy, and;
  • Education on healthy eating for people with chronic lung conditions.

Stopping smoking

Smoking not only increases the risk of developing ILD, but can also make your symptoms worse, and cause the condition to progress more quickly.

If you smoke, your doctor can advise you on treatments and options to help you quit smoking. It is also important to avoid other people's second-hand smoke.

Medications

Medications may be recommended to try to help reduce the inflammation and the healing responses that damage the lung.

Medications include:

These medications have varying rates of success, depending on the type of ILD, but can also have significant side effects. In some cases, particularly if symptoms are mild, your doctor may recommend not using medications and instead simply monitoring your condition.

There is much ongoing research into finding new, more effective medications for ILD. Your doctor may discuss with you whether participating in a clinical trial of one of these medications might be appropriate for you.

Oxygen therapy

If your blood oxygen levels are lower than normal, oxygen therapy can help to reduce breathlessness and the effects on the body.

Oxygen therapy can reduce breathlessness.Oxygen therapy can reduce breathlessness caused by interstitial lung disease. 

Lung transplantation

For cases of ILD that cannot be managed by other methods, a lung transplant may be recommended, particularly for young people.

Allergens

An environmental substance that, although not harmful in itself, elicits a vigorous reaction from the immune system.

Corticosteroids

A medication that resembles the cortisol hormone produced in the brain. It is used as an anti-inflammatory medication.

Immunosuppressant

A drug or condition that dampens the normal responses of the immune system.

Inflammation

A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.

Lungs

The pair of organs in the chest responsible for breathing.

Physiotherapist

A healthcare professional trained in treating injury or disability with physical remedies, such as massage or exercise.

Transplant

The transfer of an organ or tissue from one body to another, or from one part of the body to another, for therapeutic purposes.

Exercise physiologist

A healthcare professional trained to assess and address factors that affect participation and performance during exercise and sport.

Potential complications

Pneumonia

People with interstitial lung disease can be more vulnerable to respiratory infections and developing pneumonia. Vaccination for pneumonia and flu is an important preventative measure that can help you stay well.

Anxiety and depression

Living with a chronic lung condition can be challenging; people with ILD can be at increased risk of mental health issues such as anxiety and depression. Support groups, counselling or medication may help. If these issues are affecting you, talk to your doctor.

Pulmonary hypertension

Pulmonary hypertension occurs when damage to the small blood vessels of the lungs leads to an increase of pressure in the pulmonary artery (the main artery supplying the lungs with blood).

It is a serious condition that can place strain on the right ventricle of the heart and eventually lead to failure of the heart muscle (a type of heart failure). This may require treatment with medication, oxygen therapy or surgery, and can eventually lead to complete respiratory failure and death.

Lung cancer

ILD can, in some cases, lead to lung cancer.

Anxiety

A feeling of tension, nervousness and dread about future events. It can trigger physical symptoms such as a rapid pulse or breathing difficulties.

Artery

A blood vessel carrying blood saturated with oxygen from the heart to the body's tissues.

Lungs

The pair of organs in the chest responsible for breathing.

Vaccination

The practice of administering a vaccine, a solution containing a microorganism (that causes a specific disease) in a dead or weakened state, or parts of it, for the purpose of inducing immunity in a person to that microorganism.

Ventricle

1. The two main heart chambers that eject blood back out of the heart. 2. A series of connecting cavities in the brain that contain the cerebrospinal fluid, which supports and protects the brain.

Respiratory infections

An infection affecting the respiratory tract, which includes the mouth, nose, throat, lungs and airways.

Pulmonary artery

The artery that travels between the heart and the lungs.

Prognosis

Once lung tissue is damaged by interstitial lung disease, the damage cannot be reversed, although treatments can help to manage symptoms and, in some cases, slow the progress of the condition.

Different forms of ILD progress at different rates and some respond to treatment better than others.

Prevention

Steps that may help to prevent some cases of interstitial lung disease include:

  • Not smoking, or giving up smoking if you do, and;
  • Following safety precautions with pollutants such as asbestos, silica and bird droppings.