Pulmonary fibrosis is a term that describes the formation of scar tissue within the lungs.
It usually occurs around the small air sacs (alveoli) of the lungs. The alveoli are important for the transfer of oxygen and carbon dioxide to and from the lungs and the bloodstream. Over time, the scar tissue builds up around the alveoli, making it harder for oxygen to pass from the lungs to the body where it is needed.
This results in feeling short of breath. At first, this may occur with more strenuous activities or walking uphill or stairs. However as the fibrosis increases, you may notice you are breathless with light activities, including washing and dressing, eating and talking.
Idiopathic pulmonary fibrosis (IPF) is the commonest form of pulmonary fibrosis. Some other terminology may be used. IPF used to be called cryptogenic fibrosing alveolitis or CFA. The pattern of fibrosis seen on CT scan or lung biopsy may be referred to as usual interstitial pneumonia (UIP).
As the term idiopathic suggests, the cause of IPF is unknown. IPF is a progressive, scarring lung disease that is incurable. The middle and lower parts of the lungs tend to be affected first. As IPF progresses, the lungs slowly become much stiffer and develop a “honeycomb” appearance that can be seen on a CT scan.
In some people the scarring develops very quickly, whilst in others it happens over a longer period of time.
On average, an individual with IPF has a life expectancy of 3-4 years.
Who gets IPF?
IPF usually affects people over the age of 50 years and is slightly more common in men than women.
Studies have demonstrated the IPF is more common in people who have smoked and in association with certain occupations that involve exposure to wood or metal dust. Occasionally it can occur in younger people, especially if there is a family history of pulmonary fibrosis.
In the UK, there are approximately 5000 new cases of IPF each year. The number of cases of IPF is increasing not only in the UK, but also in the USA and Europe. We do not understand why this is happening.
Symptoms and Signs of IPF
The most common symptom is shortness of breath. In early IPF, this may occur with more strenuous exercise or walking uphill or stairs. However as the disease progresses, you may notice breathlessness with milder activities such as washing and dressing, talking and eating.
Some people suffer from a cough which is typically dry and tickly cough. Some people with IPF may have a cough productive of phlegm.
Other symptoms may include fatigue or unintentional weight loss.
What are the signs of IPF?
A sign is something abnormal that your doctor or nurse finds on a physical exam.
- Finger clubbing – this is the widening and rounding of the fingernails or toenails. This occurs in up to 60% of people with IPF. The reason is unknown.
- “Velcro-like” crackles – these are usually heard in the lower part of the lungs on listening to the chest with a stethoscope.
How is IPF monitored?
The rate of progression of IPF varies considerably from one person to the next. For some people, the disease may not change much over several months, whereas others may have a rapidly worsening form of IPF. At the time of diagnosis, it can be very difficult to predict how IPF will behave. For this reason, your lung disease will be monitored regularly. At present, changes in the lung function or breathing tests forced vital capacity (FVC) and gas transfer (TLCO or DLCO) are the most sensitive way of detecting progression of IPF.