What is thunderstorm asthma?

Thunderstorm asthma is asthma triggered when thunderstorm conditions leave a mixture of grass pollen particles in the air. Breathing in these small particles may trigger asthma. You can get thunderstorm asthma even if you have never had asthma before.

Thunderstorm asthma usually affects people in the windy period before rain starts in a thunderstorm. It usually happens in spring and early summer.

The chance of having thunderstorm asthma is highest for adults who are sensitive to grass pollen and have seasonal hay fever. You can get thunderstorm asthma even if you have no previous asthma, undiagnosed asthma or known asthma.

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.

What are the symptoms of thunderstorm asthma?

Symptoms of thunderstorm asthma include:

• shortness of breath
• tightness in your chest
• wheezing
• persistent (ongoing) cough

The symptoms of thunderstorm asthma can get worse very quickly.

What causes thunderstorm asthma?

Thunderstorm asthma 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 in.

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

When should I see my doctor?

If you have asthma, and using your regular asthma medicine does not ease symptoms during or following a thunderstorm, you should see your doctor.

If you experience asthma symptoms for the first time during a thunderstorm, you should see your doctor.

How is thunderstorm asthma diagnosed?

To diagnose thunderstorm asthma, your doctor will ask you questions to get your medical history. They will also do some tests to see how well you can breathe and how inflamed (swollen) your airway is.

If your doctor can't confirm your diagnosis, they may refer you to an allergy specialist. They may recommend that you have allergy testing to confirm a rye grass pollen allergy.

How is thunderstorm asthma treated?

If you experience thunderstorm asthma, you should follow your asthma action plan (if you have one) and use your asthma inhaler as prescribed.

You can lower your chance of developing thunderstorm asthma by lowering your exposure to pollen and keeping hay fever under control.

If thunderstorm asthma is causing recurrent, severe symptoms, you may need to see an allergy specialist. They may recommend allergen immunotherapy.

Can thunderstorm asthma be prevented?

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 medicines 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.

People at risk of thunderstorm asthma should carry an asthma reliever during the pollen season. If you've been prescribed an asthma preventer, make sure you take it as prescribed.

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

• Bureau of Meteorology (BOM) website or the BOM Weather app
• Australian Pollen Allergen Partnership, which shares pollen count in some cities
• AirRater app, which links your symptoms to weather conditions, like pollen counts, and can notify you of triggers

If a thunderstorm is approaching and it's a high pollen count day, you can:

• make sure you have your reliever medicine with you
• stay inside, especially when it is windy before the rain
• close your doors and windows
• turn off your air conditioner, or set it to recirculate air

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

What are the complications of thunderstorm asthma?

Severe asthma attacks can be life-threatening. Keeping on top of your asthma management can reduce the chance of severe flare-ups.

Even without severe flare-ups, asthma that is not controlled properly can have a negative effect on your life. Complications may include:

• tiredness or exhaustion
• poor sleep
• being less productive at work or while studying
• being unable to exercise and be physically active
• reduced lung function
• poor mental health

Taking your medicines exactly as prescribed is important. If you feel that your asthma is affecting your quality of life, contact your doctor. They can review your medicines.

Resources and support

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

For more information about asthma first aid see the National Asthma Council Australia website.

You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.