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).
What happens
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.
Possible triggers
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 in the UK. However, according to the British Lung Foundation, the number of cases seems to be rising. The reason for this is not clear.
The condition mostly affects middle-aged people aged 50 and over, and is more common in men and those who are smokers.
Outlook
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.
