Overview
Interstitial lung disease (ILD) is the name for a large group of conditions that inflame or scar the lungs. The interstitium is the thin tissue around the tiny air sacs and the small blood vessels beside them. When it thickens and stiffens, oxygen cannot pass easily into the blood and breathing becomes harder.
The scarring is called pulmonary fibrosis. The most common type, idiopathic pulmonary fibrosis (IPF), has no known cause. ILD can range from mild to life-threatening, so finding the exact type matters.
Symptoms
- Shortness of breath, at first with activity
- A dry cough that does not go away
- Chest discomfort
- Extreme tiredness
- Fingertips that look rounded, with nails that curve over them (clubbing)
Symptoms usually start slowly and get worse over time, and the pace varies a lot from person to person.
When to see a doctor
See a doctor soon if breathlessness is getting worse with everyday activity or when lying down, if a dry cough has lasted three weeks or more, or if fingertips have become rounded. Mention any dust, fumes, asbestos or mould at work or at home, any autoimmune disease, a relative with pulmonary fibrosis, and all your medicines, as these can point to the cause.
Causes
Many things can inflame or scar the lungs, and in some people no cause is found. Known causes include:
- Dust and particles breathed in over years, such as coal dust, silica, asbestos, metal fumes, farm dust and mould
- Autoimmune diseases, in which the body's defences attack its own tissues
- Some medicines
- Genes, as some types run in families
- Other medical conditions
Risk factors
- Working with dust, fumes, asbestos or silica, for example in mining, farming or welding
- Mould or dust at home
- An autoimmune disease
- Taking medicines that can affect the lungs
- A close relative with pulmonary fibrosis
- Older age and being male, in IPF
Complications
Because scarring does not heal, lung function can fall over time. Complications can include:
- Low oxygen levels in the blood, sometimes needing oxygen at home
- Chest infections
- Pulmonary hypertension, which is high in the blood vessels of the lungs
- Heart failure
Some types get worse over time and can be life-threatening, which is why early diagnosis matters.
Prevention
Not every type can be prevented. These steps help to protect the lungs:
- Not smoking
- Using a respirator correctly, and following safety rules, where there is dust, fumes or asbestos
- Watching for damp, mould and poor air quality at home
- Telling your doctor about every medicine you take, and about new breathlessness or cough after starting one
- Keeping up with the flu and pneumococcal vaccines once diagnosed
Diagnosis
Diagnosis can take time because there are so many types. The doctor asks about symptoms, work, family history and medicines, and listens to the chest. Tests may include:
- Breathing tests, such as
- A chest X-ray, then a to look for scarring
- Blood tests, including tests for autoimmune disease
- Genetic testing, in some people
- Bronchoscopy, in which a thin flexible tube is passed into the airways
- A lung , if the cause is still unclear
Treatment
Treatment depends on the type of ILD, its cause and how severe it is. It cannot repair scarring that has already formed, but treating early can slow or stop further damage and protect lung function.
If a trigger is found, such as dust or a medicine, avoiding it comes first. Medicines that calm inflammation or the immune system are used for some types. For IPF, antifibrotic medicines can slow the scarring and need regular blood tests.
Oxygen therapy eases breathlessness and helps people stay active. Pulmonary rehabilitation, with exercise and education, helps too, as do not smoking, staying as active as possible, eating well and keeping vaccinations up to date. In severe cases a lung transplant may be considered.
Myths and facts
Things people often say about this. Open each one to see what is true.
Myth“Breathlessness and a dry cough in an older person are just part of ageing.”What is true?
Fact
Getting a little slower with age can bring some breathlessness, but a cough that does not go away, or breathlessness that keeps getting worse, should be checked. Interstitial lung disease can be found with a scan and breathing tests, and early treatment can help slow lung damage.
Myth“The scarring is a lung infection like TB, so the right medicine will clear it.”What is true?
Fact
Interstitial lung disease is scarring or inflammation of the lung tissue, from causes such as dust, autoimmune disease or medicines, or from no known cause. It is not an infection, so it is treated differently. Tests such as a CT scan and breathing tests help to tell it apart from an infection.
Myth“Treatment will make the scarred lung heal and return to normal.”What is true?
Fact
Treatment does not repair scarring that has already formed. What it can do is slow or stop further damage, ease symptoms and help people stay active, which is why starting early matters.
Myth“Only people who work in mines or factories get it.”What is true?
Fact
Dust at work is one cause, but it is not the only one. Interstitial lung disease can also come from mould, autoimmune diseases, some medicines and genes, and the most common type, idiopathic pulmonary fibrosis, has no known cause.
Questions to ask your doctor
Tick the ones you want answered and take them with you.
Common questions
Is interstitial lung disease the same as pulmonary fibrosis?
Pulmonary fibrosis means scarring of the lungs. Interstitial lung disease is the wider group of conditions that inflame or scar the lung tissue, and many of them lead to fibrosis. Idiopathic pulmonary fibrosis (IPF) is the most common single type.
Can the scarring be reversed?
No. Treatment cannot repair scarring that has already formed, but it can slow or stop further damage, ease symptoms and help people stay active. Starting early gives the best result.
Does it run in families?
Genes play a part in some types, and having a close relative with IPF may raise the risk. If a relative is affected, tell your doctor, who can advise on what, if anything, to test.
Will I need oxygen at home?
Not everyone does. Oxygen is used to ease breathlessness and help people stay active, and your doctor will check your oxygen levels to decide. It can be given at home, as a portable device, or both.