Thunderstorm asthma is thought to be triggered by a unique combination of high pollen levels and a certain type of thunderstorm, causing a large number of people to develop asthma symptoms over a short period of time. 

Grass pollen grains get swept up in the wind and carried for long distances. Some can burst open and release tiny particles that are concentrated in the wind gusts that come just before a thunderstorm. These particles are small enough to be breathed deep into the lungs and can trigger asthma symptoms, making it difficult to breathe.

This can become very severe, very quickly and many people may require medical help at the same time, placing a lot of pressure on health services. 

These events are uncommon and don’t occur every year. In south-east Australia they can happen during grass pollen season (October to December).

Thunderstorm asthma can affect those with asthma or hay fever – especially people who experience wheezing or coughing with their hay fever. People with hay fever in Victoria and south-eastern Australia are likely to be allergic to grass pollen, and are therefore at increased risk of thunderstorm asthma.

Even if you don't think you have asthma or hay fever, don't ignore symptoms such as shortness of breath - check with your GP.  

How to protect yourself

All people at increased risk of thunderstorm asthma should:

  • avoid being outside during thunderstorms from October to December – especially in the wind gusts that come before the storm. Go inside and close your doors and windows, and if you have your air conditioner on, turn it to recirculate
  • have an asthma action plan (if advised by your GP) and have practical knowledge of the four steps of asthma first aid 
    (download chart here).
  • have reliever medication appropriately available in grass pollen season and be aware of how to use it (ideally with a spacer)
  • download the Vic Emergency app and set up a 'watch zone' for your location to make sure you're notified before an epidemic thunderstorm asthma event occurs.  

If you have hay fever, understand that you are at increased risk of asthma. If you think you may have symptoms of asthma then talk to your GP. 

If you have hay fever only, see your GP or pharmacist about a hay fever treatment plan and what you can do to help protect yourself from the risk of thunderstorm asthma. This may include having an asthma reliever puffer – these are available from pharmacies without a prescription.

What are the symptoms of asthma and hay fever?

People with asthma may experience one or more of the following common symptoms:

  • Wheezing – a high-pitched sound coming from the chest while breathing
  • Breathlessness
  • Feeling of tightness in the chest
  • Persistent cough

These symptoms mean that a person’s lungs are affected. 

You don’t need to have all of these symptoms to be diagnosed with asthma and not every person experiences the same symptoms. Asthma symptoms can also come and go over time.

Signs of an asthma emergency

When a person: 

  • finds it very difficult to breathe (gasping for air)
  • is unable to speak comfortably or if their lips are turning blue
  • has symptoms that get worse very quickly
  • is getting little or no relief from their reliever inhaler

People with hay fever may experience one or more of the following common symptoms:

  • Runny nose
  • Itchy nose
  • Sneezing
  • Itchy, watery eyes

These symptoms mean that a person’s eyes and upper airways are affected. Hay fever does not include symptoms such as wheezing or shortness of breath.

Could I have asthma?

Asthma affects about one in nine people and can start at any age, including adulthood. It is important to recognise asthma symptoms and see your GP for review if you experience any of them. 

A diagnosis of asthma is more likely if you have eczema or hay fever, or have close relatives with allergies and/or asthma, and 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, and
  • improve quickly with reliever medication

About one in four people with hay fever also have asthma

Four steps of asthma first aid

  1. Sit the person upright.
  2. Give four puffs of blue or grey reliever puffer. Make sure you shake the puffer, put one puff into a spacer and get the person to take four breaths from the spacer. Repeat this until the person has taken four puffs.
    Remember: shake, one puff, four breaths.
    If you don’t have a spacer simply give the person four puffs of their reliever directly by mouth.
  3. Wait four minutes. If there is no improvement, give four more separate puffs as in step 2. Remember: shake, one puff, four breaths
  4. If there is still no improvement, call 000 for an ambulance. Tell the operator that someone is having an asthma emergency. Keep giving the person four separate puffs of reliever medication, taking four breaths for each puff, every four minutes until the ambulance arrives.

If you are not sure if someone is having an asthma attack, you can still use asthma reliever medication because it is unlikely to cause harm.


Call 000 immediately if the person is not breathing, if their asthma suddenly becomes worse, or if the person is having an asthma attack and there’s no blue or grey reliever available.

Community education sessions 

Asthma Australia is holding information sessions on thunderstorm asthma between now and 1 December 2017.

Find a session near you

Where to get help

  • In an emergency, always call 000
  • Emergency department of your nearest hospital
  • Your GP
  • Your nearest pharmacy (for medication)
  • Nurse-On-Call: Phone 1300 60 60 24 – for expert health information and advice at all hours
  • National Home Doctor Service: Phone 13 SICK (13 7425) for after-hours home GP visits (bulked billed)
  • Asthma Australia Helpline: Phone 1800 ASTHMA (1800 278 462)


For more general health information, visit Better Health Channel at