Interstitial lung diseases and lung fibrosis
In interstitial lung diseases, the tissue between the air sacs becomes inflamed or scarred and stiff, causing shortness of breath and a dry cough. This page explains what this group of diseases is, how it is assessed with CT and other tests, what treatment looks like overall and when to get urgent help.
What are these diseases?
Interstitial lung diseases (ILD) are a family of diseases that inflame or scar the tissue between the air sacs and the blood vessels around them. The NHLBI writes that this thickening of the tissue makes it harder for oxygen to reach the blood and for carbon dioxide to leave. Some forms are mild and some serious. Fibrosis means this scarring.
The symptoms, according to the NHLBI and NHS: shortness of breath, a dry cough, tiredness, sometimes chest discomfort and a change in the shape of the fingertips (nail clubbing). They usually start gradually. The ATS says shortness of breath with activity is the main sign, appearing most when walking briskly, climbing stairs and going uphill.
The causes vary. The ATS and NHLBI name autoimmune diseases, exposure to dust and substances at work or at home, side effects of some medicines, and heredity. In many cases no cause is found even after a full work-up, and it is called “idiopathic”. The most common type is idiopathic pulmonary fibrosis (IPF). The ATS writes that it is usually diagnosed between the ages of 50 and 80, and the NHS says it mainly affects people aged 70 or over. According to the ATS it is more common in men and in people who have smoked or worked in a dusty environment. The ATS says it sometimes runs in families.
Who should be seen?
The NHS says to see a doctor if you are worried about IPF, your shortness of breath gets worse during ordinary tasks or when lying down, or you have a cough that has lasted three weeks or more. The ATS also writes that you should discuss shortness of breath or a cough that does not go away with a doctor.
How is it assessed?
The ATS writes that diagnosis proceeds like this:
- A chest CT with thin slices (called HRCT in the sources) is the first step.
- A careful history: symptoms, medicines you take, work and environment (anything at home or work that might scar the lungs), and family history. With a stethoscope the doctor often hears fine crackling sounds (crackles).
- Blood tests for markers of autoimmune disease. The ATS stresses that no blood or genetic test alone exists to diagnose IPF.
- Lung tests: a breathing test and oxygen measurement (such as a walking test) assess severity and follow the course, but do not diagnose by themselves.
- A heart ultrasound (echo) in more advanced stages, to look for heart complications.
- Bronchoscopy or a surgical biopsy only for some patients. Bronchoscopy is explained in its own guide.
The ATS says the final diagnosis is usually made by a specialist with experience in lung fibrosis, and often the patient is reviewed in a joint meeting of the lung doctor, radiologist and pathologist. See the “Lung tests” guide for an explanation of each test.
What does treatment look like overall?
The NHLBI writes that treatment depends on the type of disease and the severity of symptoms, and does not reverse existing scarring, but early care can slow or stop progression. If an environmental cause is found, staying away from it is part of treatment. The other tools, according to the NHS and ATS:
- Medicines that some IPF patients take so that scarring progresses more slowly. Taking them requires regular blood tests, and the decision is up to the specialist.
- Oxygen, at home or portable, when blood oxygen is low.
- Pulmonary rehabilitation: education and exercise.
- Lung transplant, only in a few cases where the disease progresses.
The ATS writes that IPF is a serious disease and its course varies from person to person. The NHS says that with effective treatment some patients have few symptoms for years. Only your treating doctor can speak about your own outlook.
What can you do yourself?
- Give up cigarettes and hookah, and if you want help, ask your doctor (ATS, NHS).
- Regular physical activity and a balanced diet (NHS). Consult your doctor before starting an exercise programme.
- Have the vaccines your doctor says. The NHS names flu and pneumococcal and says to stay away, as far as possible, from people who have a cold or a chest infection.
- Do not stop any medicine your doctor has given without advice. If you have a side effect, tell your doctor.
- If you are given oxygen, use it only as prescribed and away from fire and cigarettes.
- If you are exposed to dust or mould at work or at home, tell your doctor; this information helps diagnosis.
Discuss any supplement or product you want to take alongside your treatment with your doctor before starting.
When to get urgent help
Call 115 (Iran’s emergency number) right now or go to the emergency department if:
- You are gasping for breath and cannot talk or finish a sentence.
- Your lips or skin have turned blue, grey or very pale.
- You have sudden shortness of breath together with chest pain or a painful, swollen leg.
- You are coughing up blood-stained phlegm, more than a few spots.
- You have suddenly become confused.
The NHLBI writes that some IPF patients have an “acute exacerbation”, meaning a sudden and severe worsening of their condition. If that happens, do not wait for a clinic appointment.
See a doctor the same day if your shortness of breath has clearly got worse over a few days, you have a fever and a new cough, or ankle swelling has increased. If you cannot reach a doctor, go to the emergency department. The full list is in the “When should I call urgently?” guide.
Frequently asked questions
What does lung fibrosis mean?
Fibrosis means scarring of tissue. The ATS explains that this scarring happens in the 'interstitial' tissue of the lung, the supporting framework of the air sacs. The tissue becomes thick and stiff, the sacs cannot open fully, and the passage of oxygen into the blood is also limited. Once it has formed, the scarring is not reversible; the aim of treatment is to slow the process and reduce symptoms.
Is my dry cough and shortness of breath definitely fibrosis?
No. The ATS says shortness of breath, cough and tiredness also occur in more common diseases, and these must be ruled out before fibrosis is diagnosed. The NHS also says patients should not guess the cause of their shortness of breath themselves. That is why the doctor clarifies the cause with an examination, CT and tests.
Is interstitial lung disease all one type?
No. The NHLBI writes that interstitial lung diseases are a family of diseases with different causes: heredity, lifestyle, environmental exposure, some medicines and other diseases. Many have no known cause, and the most common of them is idiopathic pulmonary fibrosis (IPF). Dust and mould can set off some types, such as hypersensitivity pneumonitis. Treatment depends on the type of disease.
Is a biopsy always needed for diagnosis?
Not always. The ATS writes that diagnosis starts with a thin-slice CT, a history, blood tests and a specialist's examination, and only some patients need bronchoscopy or a surgical biopsy. The NHS also says these are used when the cause is not clear from other tests. The decision is up to the doctor.
Is there treatment for this disease?
The NHS and NHLBI say there is no treatment that reverses the scarring, but treatment can slow progression and reduce symptoms. The NHS names two medicines given to some patients to slow the scarring, along with oxygen and pulmonary rehabilitation. The ATS writes that IPF treatment has improved over the past decade. What suits you is determined by the specialist doctor.