Being referred for lung function testing can raise questions or concerns, particularly if you have never had the tests before. Many patients worry about what the tests involve, whether they will be uncomfortable, or what the results might mean. Understanding the purpose and process of lung function testing can help reduce anxiety and ensure you feel confident attending your appointment.

Lung function tests are a key diagnostic tool used by respiratory specialists to assess how well your lungs are working. They provide valuable information that helps guide diagnosis, treatment decisions, and long-term management of respiratory conditions.

What are lung function tests?

Lung function tests measure how effectively your lungs move air in and out and how well oxygen is transferred into your bloodstream. These tests help identify whether breathing difficulties are caused by airway narrowing, lung stiffness, muscle weakness, or other factors.

They are commonly used to:

• Investigate symptoms such as breathlessness, cough, or wheeze
• Diagnose respiratory conditions
• Monitor response to treatment
• Track changes in lung health over time
• Assess suitability for certain procedures or medications

The tests are non-invasive and are performed by trained respiratory scientists using specialised equipment.

Common reasons your doctor may request lung function testing

Your GP or specialist may recommend lung function tests if you experience:

• Persistent shortness of breath
• Chronic or unexplained cough
• Wheezing or chest tightness
• Reduced exercise tolerance
• Frequent chest infections
• Abnormal findings on imaging

They may also be requested if you have a known respiratory condition such as asthma or COPD, or if your doctor wants to establish a baseline measurement of your lung health.

Types of lung function tests you may encounter

There are several types of lung function tests, each providing different information. Not all patients require every test — your specialist will recommend those most relevant to your symptoms.

Spirometry This is the most commonly performed lung function test. It measures how much air you can breathe out and how quickly. You will be asked to take a deep breath and blow forcefully into a mouthpiece.

Spirometry helps identify airflow obstruction or restriction and is commonly used in the diagnosis of asthma and COPD.

Gas transfer testing This test measures how effectively oxygen passes from your lungs into your bloodstream. It can help identify conditions affecting the lung tissue itself, such as interstitial lung disease.

Lung volume testing Lung volume tests assess how much air your lungs can hold. This can help distinguish between different causes of breathlessness and identify restrictive lung conditions.

Bronchodilator response testing In some cases, spirometry is repeated after inhaling medication to see how your lungs respond. This can help determine whether symptoms are reversible, which is important in diagnosing asthma.

What happens during your appointment?

Your lung function testing appointment typically begins with a brief explanation of the tests and confirmation of relevant medical history. The respiratory scientist will explain each step clearly and guide you throughout.

During testing:

• You will sit comfortably and wear a nose clip
• You will breathe through a disposable mouthpiece
• You may be asked to repeat certain breathing manoeuvres several times
• Breaks are provided if needed

The tests are effort-dependent, meaning your cooperation and understanding are important. The scientist will encourage you and ensure results are accurate and reliable.

Are lung function tests uncomfortable?

Most patients tolerate lung function testing very well. Some people may feel slightly light-headed or short of breath briefly due to the breathing manoeuvres, but this usually settles quickly.

The tests are safe, and staff monitor you throughout. If you feel unwell or need to pause, you can let the scientist know at any time.

Preparing for lung function tests

You may be given specific instructions before your appointment. These can include:

• Avoiding certain inhalers for a set period (if advised by your doctor)
• Wearing comfortable clothing
• Avoiding large meals immediately beforehand
• Refraining from smoking before testing

If you are unsure about preparation, the clinic can provide guidance prior to your appointment.

Understanding your results

Lung function test results are complex and are interpreted by your respiratory specialist in the context of your symptoms, medical history, and other investigations.

Results may indicate:

• Normal lung function
• Airflow obstruction
• Lung restriction
• Reduced gas transfer

Your specialist will explain what your results mean for you, whether further tests are required, and how they influence your treatment plan.

Why lung function tests are so important

Lung function tests provide objective information that cannot be obtained from symptoms alone. They help ensure diagnoses are accurate and treatments are appropriate.

They are also valuable for monitoring conditions over time, allowing specialists to detect changes early and adjust management accordingly.

Lung function testing as part of coordinated care

At South Australian Medical Specialists, lung function testing is integrated into broader respiratory care. Results are reviewed alongside imaging, sleep studies, and clinical assessments to provide a complete picture of lung health.

This coordinated approach supports accurate diagnosis, reduces unnecessary testing, and helps patients feel informed and supported.

Reassurance for patients

If you have been referred for lung function testing, remember that the tests are a tool — not a diagnosis in themselves. Many people undergo lung function testing and are reassured by normal or mild findings.

The purpose of testing is to provide clarity, guide care, and support better breathing and overall health.