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Thunderstorm asthma

5-minute read

What is thunderstorm asthma?

Thunderstorm asthma is triggered by a mixture of grass pollen in the air and thunderstorm conditions.

It happens when pollen grains are drawn up into the clouds as a thunderstorm forms. The pollen grains absorb water, swell and burst open. Particles containing pollen allergens are released. The wind can push these tiny particles down to ground level where they can be breathed into the lungs.

Thunderstorm asthma usually affects people in the windy period before the rain starts. It usually happens in spring and early summer. Even people who have never had asthma before can get thunderstorm asthma.

If your symptoms become severe call triple zero (000) and ask for an ambulance — say it is an asthma emergency.

Watch this video from Better Health Channel about thunderstorm asthma. It's also available with subtitles in languages other than English on the Health Translations website.


Who gets thunderstorm asthma?

The risk of thunderstorm asthma is highest in adults who are sensitive to grass pollen (particularly rye grass pollen) and have seasonal hay fever.

Thunderstorm asthma can happen in people of any age.

What are the symptoms of thunderstorm asthma?

If you have thunderstorm asthma, you might have one or more of these symptoms:

  • shortness of breath
  • tightness in your chest
  • wheezing when you breathe
  • persistent coughing

The symptoms of thunderstorm asthma can get worse very quickly. If breathing becomes difficult, call 000 for an ambulance.

CHECK YOUR SYMPTOMS — Use the Symptom Checker and find out if you need to seek medical help.

What should I do if I have thunderstorm asthma?

If you are experiencing thunderstorm asthma, follow these instructions.

If the symptoms are moderate or mild, begin asthma first aid using your asthma reliever inhaler (if you have one).

Take any hay fever preventer medication, such as a nasal spray containing corticosteroid or antihistamine as directed

If your breathing problems are severe, call triple zero (000) and ask for an ambulance — say it is an asthma emergency. If you have a reliever inhaler you should begin asthma first aid.

If you are with someone who is experiencing asthma symptoms, sit the person upright and follow the instructions above. Stay with them and be calm and reassuring.

Can I prevent thunderstorm asthma?

If you have asthma or hay fever, you can help protect yourself from thunderstorm asthma by managing these conditions and planning for emergency situations.

See your doctor to develop an asthma action plan or hay fever treatment plan.

Your plan should include what preventive medications you can take to manage your condition and what you should do in an asthma emergency. You should review your treatment plan regularly with your doctor.

Your doctor may refer you to an allergy specialist if you’ve had symptoms of thunderstorm asthma. They may recommend that you have allergy testing to confirm if you are allergic to rye grass pollen. Specialised treatment (immunotherapy) for rye grass allergy may be an option.

People at risk of thunderstorm asthma should carry an asthma reliever medicine during the pollen season. Asthma preventer medicine may also be recommended.

How can I avoid thunderstorm asthma triggers?

You can check weather forecasts and pollen counts with these sources:

If a thunderstorm is approaching you and it’s a high pollen count day, it is a good idea to:

  • make sure you have your reliever medication with you
  • stay inside, especially when it is windy before the rain
  • close your doors and windows
  • if an air conditioner is on, set it to recirculate air

Face masks don’t protect you against the tiny particles that cause thunderstorm asthma.

When should I seek help for thunderstorm asthma?

If your breathing problems are severe, call triple zero (000) and ask for an ambulance — say it is an asthma emergency.

Information about thunderstorm is also available in languages other than English on the Health Translation website.

Learn more here about the development and quality assurance of healthdirect content.

Last reviewed: May 2022


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Need more information?

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Top results

Thunderstorm asthma - Better Health Channel

People who have asthma or hay fever can get severe asthma symptoms during pollen season when high grass pollen counts combine with a certain type of thunderstorm.

Read more on Better Health Channel website

Hay fever and pollen - Asthma Australia

Hay fever is an allergic reaction to particles found in the air that you breathe. These particles are breathed in through your nose or mouth.

Read more on Asthma Australia website

Thunderstorm asthma - Australasian Society of Clinical Immunology and Allergy (ASCIA)

It seems reasonable to think that rain would relieve allergic rhinitis (hay fever) and asthma triggered by pollen, by washing pollen out of the air. However, rain from some thunderstorms can make some people's symptoms worse. Epidemics of thunderstorm asthma in Australia have occurred in Melbourne and Wagga Wagga.

Read more on ASCIA – Australasian Society of Clinical Immunology and Allergy website

Thunderstorm asthma - Asthma Australia

To lower the chance of having thunderstorm asthma when it is a known trigger for you, it is best to have good asthma management year-round. 

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Epidemic thunderstorm asthma - Better Health Channel

Find out when thunderstorm asthma events take place, risks, symptoms and how to protect yourself and others. What people with hay fever and asthma should know.

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Pollen - a trigger for hay fever - National Asthma Council Australia

Plant pollen is well known as a trigger for seasonal allergic rhinitis (hay fever) and seasonal allergic conjunctivitis.

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Hay fever treatments - MyDr.com.au

Antihistamines work fast and are good at treating mild symptoms of hay fever, such as sneezing and runny nose, whereas corticosteroid nasal sprays may take several days to work.

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Thunderstorm asthma - National Asthma Council Australia

If you are allergic to ryegrass pollen, you need to be taking preventive asthma treatment well before the onset of springtime thunderstorms and the pollen seaso

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Allergic rhinitis (hay fever) and sinusitis - Australasian Society of Clinical Immunology and Allergy (ASCIA)

Allergic rhinitis, hay fever, sinusitis, pollen

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Pollen allergy - Australasian Society of Clinical Immunology and Allergy (ASCIA)

Pollen from grasses, weeds or trees can trigger symptoms of hayfever and asthma. Pollen seasons can last for several months and exposure is difficult to avoid.

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