SummaryRead the full fact sheet
- Doctors do not use one specific test to diagnose asthma.
- To diagnose asthma, your doctor will take your medical history and order some lung function tests.
- A lung function test measures airflow in and out of the lungs, and will help your doctor to diagnose asthma.
- You should take your child to the doctor if you are concerned about any breathing problems they may have.
- A lung function test is not usually possible in children younger than 5 years.
- Diagnosing asthma in very young children can be difficult.
On this page
Asthma symptoms include:
- difficulty breathing
- shortness of breath.
These symptoms can become severe and lead to a life-threatening asthma emergency.
Asthma symptoms are caused by the muscles tightening around the airways, and swelling and mucus production inside the airways. People with asthma have airways that are sensitive to some things that may not impact people without asthma. Things that set off or start symptoms are called triggers.
Asthma triggers can include:
Doctors do not use one specific test to diagnose asthma. Your doctor first needs to understand your symptoms and medical history. Your doctor will ask questions such as whether there is any family history of asthma, eczema or hay fever. They will also try to understand if there are any other reasons for your symptoms before making a clinical diagnosis of asthma.
In people older than 5 years, a lung function test that measures airflow in and out of the lungs will help your doctor to diagnose asthma.
Asthma is more likely to be diagnosed if your symptoms:
- keep coming back, or happen at the same time each year
- are worse at night or in the early morning
- are clearly triggered by exercise, allergies or infections, or have a seasonal pattern
- improve quickly with reliever medication.
Diagnosis of asthma in children
It’s often difficult to diagnose asthma in children under 5, particularly as they find breathing tests difficult. Your doctor will assess your child’s symptoms and your explanation of their symptoms, and may give your child asthma medicine to measure its effect – this is called a ‘treatment trial’. Your doctor will monitor the effect this medicine has on your child and will use the results as part of their diagnostic process.
Keep a record of asthma symptoms
If you or a family member have breathing difficulties, keep a diary of symptoms to discuss with your doctor. You could also make a video or audio recording of the wheezing, using your mobile phone.
The diary may include:
- when the symptoms occur – such as during the day or worse at night
- how bad the symptoms are and how often they happen
- how long the symptoms remain and whether they change with time
- whether the symptoms are worse after exercise, playing, laughing or after an infection (colds or flu)
- whether the symptoms are worse after exposure to animals, pollens or mould.
Lung function test
A lung function test ( spirometry) can help to diagnose asthma in adults and children 5 years and older. Spirometry measures air flowing in and out of the lungs to give a measure of how well your lungs work. Other conditions, such as having a cold, can also affect lung function.
To do the test, you will blow into a tube as hard as you can for a few seconds. The spirometer measures the amount of air pushed through the tube, as well as other lung measurements. Most adults and children older than 5 years are able to do this test.
Where to get help
- In an emergency, always call triple zero (000)
- Emergency department of your nearest hospital
- Your GP (doctor)
- NURSE-ON-CALL Tel. 1300 60 60 24 – for expert health information and advice (24 hours, 7 days)
- National Home Doctor Service – for after-hours home doctor visits (bulk billed) Tel. 13 SICK (13 7425)
- Asthma Australia Tel. 1800 ASTHMA (1800 278 462)
- National Asthma Council Australia Tel. 1800 032 495
- Allergy and Anaphylaxis Australia Tel. 1300 728 000
- The Royal Children's Hospital has produced a number of videos to help you better understand and manage your child's asthma.