Pulmonary function tests

Scarring and inflammation can cause the air sacs inside the lungs (alveoli) to become thicker than normal.

Sometimes, these changes can increase pressure in the blood vessels between the lungs and heart. This is pulmonary arterial hypertension (PAH), a serious condition which may cause shortness of breath, chest pain and lead to heart failure.

PAH is a rare condition but more common in people with scleroderma than the general population; early identification and treatment can slow progression.

What is it?

A pulmonary function test will assess how well your lungs work, mainly by testing your breathing.

How is it performed?

A spirometry test will measure the volume of your lungs. The maximum volume of your lungs will decrease if there is significant scarring.

A clearance test assesses how well your lungs take in oxygen and then passes into your bloodstream.

Your doctor will measure a 'gas transfer factor', which decreases if there is significant scar tissue on the lungs or if the blood vessels in the lungs are affected. Measuring this annually can tell your doctor whether your disease is stable or worsening.

What do the results mean?

Even if you don't have symptoms, it's important to get your lung function checked each year. If you do notice any changes, such as coughing or shortness of breath, inform your doctor who can arrange an earlier assessment.