Pulmonary fibrosis means scarring (thickening) of the tissue of the lung.
Scarring is part of the body's repair process and can help to heal injured areas. However, scar tissue that forms in the lungs can stop them working properly, making them less efficient at transporting oxygen into the blood and removing carbon dioxide. This often leads to breathing difficulties, which can be brought on by simple activities such as walking and talking.
Pulmonary fibrosis may be associated with a separate underlying disease, such as rheumatoid arthritis. When there is no known cause for its development, it is termed 'idiopathic'.
These pages focus on idiopathic pulmonary fibrosis (IPF).
When you breathe in, air travels down your trachea (windpipe) and into smaller tubes that branch off your trachea, called bronchi (airways). These lead to your lungs, where they divide into thousands of smaller, thinner tubes called bronchioles that end in bunches of tiny air sacs called alveoli.
The alveoli act as the place for gas exchange in the body. Oxygen in the air you have inhaled passes through the thin walls of the alveoli into the tiny blood vessels (capillaries) surrounding the alveoli.
Once in the bloodstream, oxygen attaches to red blood cells and is transported to the rest of the body. Carbon dioxide is passed from the red blood cells into the alveoli and breathed out.
Sometimes, for reasons that are not entirely clear, the cells lining the alveoli can become damaged. These cells may try to heal themselves, but the healing process becomes uncontrolled, causing unwanted thickening and scarring (fibrosis) of the alveoli and the surrounding lung tissue. This affects the gas-exchange process and leads to a lack of oxygen in the body, producing breathlessness.
Cigarette smoking, certain lung infections and gastro-oesophageal reflux disease are just some of the possible factors that can cause damage to the cells lining the alveoli (for more information, see Pulmonary fibrosis - causes).
How common is idiopathic pulmonary fibrosis?
Idiopathic pulmonary fibrosis is rare, affecting fewer than 10 in 10,000 people.
The condition mostly affects middle-aged people aged 50 and over, and is more common in men and those who are smokers.
Idiopathic pulmonary fibrosis is a long-term condition and there is no known cure. Lung scarring in this condition is usually permanent.
There may be periods when the condition remains stable, but other times when symptoms (particularly breathlessness and cough) get worse.
Treatment aims to prevent further damage to the lungs. Oxygen therapy and pulmonary rehabilitation may help to improve the daily lives of some patients with pulmonary fibrosis (see Pulmonary fibrosis - treatment for more information).
Patients can also help themselves by leading as healthy a lifestyle as possible. This includes eating well, not smoking and exercising regularly up to a level they can tolerate.
In some cases, if the condition continues to get worse despite medical treatment, a lung transplant may be considered.
The most common symptom of idiopathic pulmonary fibrosis is breathlessness, which can get worse over time.
At first, many people ignore their breathlessness (especially older patients) and blame it on getting old or being out of shape. However, as the disease progresses and damage to the lungs becomes more severe, breathlessness can develop even with minor physical activity such as getting dressed or having a shower.
Less common symptoms of pulmonary fibrosis include:
- a persistent cough
- fatigue (tiredness) and weakness
- loss of appetite and weight loss
In as many as half of cases, there is also a change in the shape of the finger and toenails. This thickening of the tissue at the base of the finger and toenails is known as clubbing. The exact cause of clubbing is unknown, but it can occur in people with various chest and heart diseases.
Heart failure can develop when the condition becomes severe. This is due to a combination of factors, including a build-up of blood in the right side of the heart (the side that pumps blood to the lungs), which develops because it is difficult to pump blood through the scarred lung tissue. The poor supply of oxygen from the diseased lungs to the heart muscle also contributes to heart failure.
Heart failure can cause various symptoms, including worsening breathlessness and fluid retention (oedema). For more information, see the Health A-Z page on Symptoms of heart failure.
'Idiopathic' means 'having no known cause'. It is not known exactly how idiopathic pulmonary fibrosis occurs or why some people are more prone to developing it.
It is thought that the condition is triggered when the cells that line the lung alveoli (air sacs) become damaged. The affected cells try to repair themselves but the process becomes uncontrolled, resulting in thickening and scarring (fibrosis) of the alveoli and surrounding lung tissue. The amount of oxygen that can pass from the lungs into the blood is then significantly reduced.
Various factors have been suggested as possible triggers for the initial damage to the cells lining the alveoli, including:
- Cigarette smoking. The disease is more common in current smokers or those who have smoked in the past.
- Viral infections such as the Epstein-Barr virus or hepatitis C.
- Gastro-oesophageal reflux disease (GORD), a condition where the acid from your stomach rises back up into your throat. This may be accidentally inhaled into the lungs, causing damage to the alveoli.
- Genetic tendency. The condition sometimes seems to run in some families, although no family history is found in 80% of cases.
Idiopathic pulmonary fibrosis can be hard to diagnose because its main symptoms are similar to those of other lung diseases. Also, little is known about the causes of this condition or how it progresses. You will usually be referred to a chest (respiratory) specialist for diagnosis.
Medical history and physical examination
Your doctor will ask about your medical history and find out whether there are any other factors that could contribute to the diagnosis of pulmonary fibrosis, such as whether you are a smoker, whether you have had a high degree of exposure to occupational contaminants or whether you have any other medical conditions.
They will do a physical examination, checking the sound of your breathing through a stethoscope. A 'crackling' sound can suggest the presence of pulmonary fibrosis. They will also look for signs of clubbing on your fingers and toes.
Lung function tests (also called pulmonary function tests) assess how well your lungs work. These tests measure how quickly you can move air in and out of your lungs, how much air they can hold and how well they transfer oxygen into and remove carbon dioxide from your blood.
The tests require you to breathe in and out of a lung function machine and the information collected will help to diagnose different lung diseases, measure their severity and check how well treatment for a particular lung disease is working.
As pulmonary fibrosis can look like other lung diseases on a scan, your consultant may need to remove a small piece of your lung to confirm the diagnosis. This is considered to be the most reliable diagnostic method for pulmonary fibrosis.
A biopsy of the lung can usually be obtained using a keyhole procedure. The modern technique is called video-assisted thoracoscopic surgery, or VATS.
VATS is performed under a general anaesthetic, so you are asleep throughout. Once you are asleep, a surgeon will make several small incisions (cuts) in your side. A thin rigid tube with a camera and a light at the end of it (endoscope) is then inserted through one of the incisions into the area between the lungs and the chest wall. The surgeon is able to see the lung tissue through the endoscope and obtain a sample, which can be examined for signs of pulmonary fibrosis under a microscope.
Chest X-rays are a good way of looking for changes or abnormalities in your lungs to help diagnose particular conditions. Although major organs and blood vessels do not show up as clearly on X-rays as bones, they are still visible.
Similar to an X-ray, a CT (computerised tomography) scan can provide a sharper and more detailed image of your lungs to help a specialist reach a diagnosis. A radiologist (doctor specially trained to interpret medical images such as X-rays) may be able to identify a honeycomb effect in the lungs. This honeycomb effect suggests lung scarring and damage to your air sacs.
Bronchoscopy is a method of looking inside your airways. A narrow, flexible tube called a bronchoscope is introduced through your nose or throat and down into your airways. The tube has an eyepiece so the doctor can see inside. The doctor then looks for anything abnormal and can take cell samples for testing. They can also take photographs of the inside of your airways if necessary.
You usually have the test under local anaesthetic. This means you are awake for the test but your throat is numbed. The procedure can be a bit uncomfortable, but it does not last long. You will be required to sign a consent form before the procedure can be done.
An echocardiogram is an ultrasound examination of your heart, which may be needed if the specialist suspects you have developed heart failure.
There is currently no cure for idiopathic pulmonary fibrosis. The main aim of treatment is to improve the symptoms of the disease as much as possible and slow down its progression.
Medication can help to reduce symptoms in some people, but does not work for everyone. Increasing evidence suggest that medications such as steroids and immunosuppresants do more harm than good. Some people, particularly elderly people whose symptoms are mild or not getting much worse, may be advised not to take any medication. This is because possible side effects could be worse than the progression of the disease.
Steroid medication is thought to improve symptoms in about one person in four with idiopathic pulmonary fibrosis. A low dose of a corticosteroid called prednisone may be prescribed. If there is no improvement after a few months, the treatment may be stopped.
Taking steroid medication, especially for a prolonged period of time, can cause side effects including:
- weight gain
- osteoporosis (brittle bones, which especially affects women after the menopause)
- cataracts (cloudy patches in the lens in the eye)
- glaucoma (an eye disease that impairs vision)
- stomach problems
It can also trigger diabetes and raised blood pressure. For more information, see the Health A-Z page on Side effects of corticosteroids.
Your doctor or specialist should always weigh up the potential benefits of steroid treatment against the risk of side effects.
Immunosuppressants are drugs that suppress the body's immune system (thought to be partly responsible for idiopathic pulmonary fibrosis), helping to stop inflammation and fibrosis. You may be prescribed the immunosuppressant drugs cyclophosphamide or azathioprine.
Taking immunosuppressant drugs can increase your likelihood of getting other infections and can cause problems with your blood, such as anaemia.
Again, your doctor or specialist should always weigh up the potential benefits of immunosuppressant treatment against the risk of side effects.
A combination of steroids and an immunosuppressant may be used in some cases as there is thought to be more chance of improvement when these drugs are used together than when either medication is used on its own. Combination therapy also allows for the dose of steroids to be lower, meaning there is less chance of severe side effects.
When idiopathic pulmonary fibrosis is severe, the levels of oxygen in your blood fall and you feel more breathless. In this case your specialist may prescribe you oxygen, which can help with your breathing and enable you to be more active.
You will need to take oxygen through nasal tubes or a mask from a portable machine called an oxygen concentrator. This device provides air with a much higher oxygen level than the air you breathe in naturally. The tubes from the machine are long, so you will be able to move around your home while you are connected.
You can also use an oxygen inhaler for when you are out and about.
Pulmonary rehabilitation is a multidisciplinary treatment (involving many different types of healthcare professionals) used for many long-term lung conditions. Courses aim to help a patient come to terms with their condition, learn the best ways to deal with it and improve their ability to function on a daily basis without extreme breathlessness.
Courses in pulmonary rehabilitation are usually held locally and may include:
- education about pulmonary fibrosis
- physical exercise
- breathing exercises
- advice on nutrition
- psychological support
- a social support network
For more information, watch the above video in which a respiratory nurse specialist and patients explain pulmonary rehabilitation.
If your condition continues to get worse despite other forms of treatment, your consultant may recommend a lung transplant. The decision to have a transplant will be based on:
- how bad your condition is
- how quickly your condition is getting worse
- your age and general health
- how much your condition is likely to improve after a transplant
- whether a donor lung is available
Few people with idiopathic pulmonary fibrosis are suitable candidates for a lung transplant. For more information on the procedure, see the Health A-Z topic on lung transplant.
As well as the medical treatments above, there are measures you can take to stay as healthy as possible: