Pulmonary Fibrosis

The most common symptom is shortness of breath, often when physically active, 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 lung damage becomes more severe, breathlessness can develop even with minor physical activity such as getting dressed or having a shower.

Other symptoms of pulmonary fibrosis include:

• a persistent dry cough
• tiredness
• loss of appetite and weight loss

In up to half of all cases, there is also a change in the shape of the finger and toenails. This thickening of tissue at the base of the finger and toenails is known as digital clubbing. The exact cause of clubbing is unknown, but it can occur in people with various chest and heart diseases.

Secondary conditions

There can also be secondary conditions related to IPF. These can include:

Chest infection – you will have an increased risk of developing chest and airway infections such as:

• bronchitis – an infection of the airway of the lungs
• pneumonia – an infection of the air sacs of your lungs
• influenza (flu)

Pulmonary hypertension

Around a third of people with IPF will also go on to develop pulmonary hypertension. Pulmonary hypertension is when blood pressure inside the arteries that connect the lungs to the heart is dangerously high.

Heart failure

Heart failure, where the heart is unable to pump enough blood around the body, 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.

It is not known exactly how idiopathic pulmonary fibrosis (IPF) occurs or why some people are more prone to developing it. Idiopathic means having no known cause.

It is thought that IPF is triggered when cells that line the lung alveoli (air sacs) become damaged. 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.

A number of 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 orhepatitis C.
• Breathing in wood dust and / or metal dust – people in occupations where this can occur, such as carpentry, have a slightly higher risk of developing IPF
• 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 appears to run in some families.

As IPF is such a rare condition it is hard to estimate how much of an impact these risk factors can have on your chance of developing IPF.

Most experts agree that the two most significant risk factors are:

• being a smoker or having smoked in the past
• exposure to wood and metal dust