Idiopathic pulmonary fibrosis (IPF)

How IPF develops

IPF is a long-term condition that causes progressive scarring in your lungs.

‘Idiopathic’ means the cause is not known and we don’t understand well the reasons why someone develops it.

Recently, our understanding of how this disease develops has increased. The scarring in the lungs was previously thought to be caused by inflammation. But trials have shown anti-inflammatory and immunosuppressant treatments are not of benefit in treating IPF, so researchers have looked for other causes.

We now believe that in people with IPF, when the lung suffers an initial injury, the body tries to heal the damaged area of lung but creates too much scar tissue. This is called fibrosis.

The initial injury might be from smoking, acid reflux from the stomach, viruses, or environmental factors such as breathing in some kinds of dusts. The scar tissue cannot currently be changed back to healthy tissue and it is not able to function properly. The more of the lung that becomes scarred, the more difficult it is for the body to transport oxygen from the air you breathe into your circulation. This causes breathlessness.

Some people may be genetically predisposed to develop IPF when their lung is injured.

We need more research to keep trying to understand in more detail the processes in the body that cause IPF. This will help us to develop new treatments.

Further information:

A review of the mechanisms of IPF can be found in this scientific paper:

Next: Disease-modifying treatments >

Last medically reviewed: February 2016. Due for review: February 2018

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.