Healthdirect Free Australian health advice you can count on.

Medical problem? Call 1800 022 222. If you need urgent medical help, call triple zero immediately

healthdirect Australia is a free service where you can talk to a nurse or doctor who can help you know what to do.

beginning of content

What causes hay fever?

3-minute read

The most common hay fever causes and triggers are discussed below; however, it’s important to note that it’s not caused by a food allergy.

House dust

House dust contains numerous organic and inorganic compounds such as house dust mites, hair, smoke, dirt, fibres, mould spores, pollen grains, insects, mammalian dander (small scales from the skin or hair of pets), as well as secreta (such as saliva) and excreta (such as faeces) from insects, mites and pets.

Of all of these compounds, house dust mites are the most widespread and are commonly found in mattresses, bed bases, pillows, carpets and upholstered furniture. Although they are present all year round, their numbers usually peak during humid periods.


Household pets, especially cats and dogs, are an important source of domestic allergens which are found in the animal’s fur and in house dust. The allergens can remain airborne for long periods of time, and people who are ‘allergic’ to these animals may also react to allergens from other animals such as horses, rabbits and guinea pigs.


Pollens are produced by trees, grasses, flowers and other plants to fertilise the female flower in order to reproduce that plant species. The type and number of pollens vary according to an area’s vegetation, geography, temperature and climate. The grass pollen season usually occurs between late September and Christmas in Australia, with most pollen in the air between 6am and noon.

Most of the pollen that causes allergies is produced by airborne pollen from introduced northern hemisphere grasses, trees and weeds such as Pellitory weed, Paterson's Curse, Ragweed and Parthenium.

Fungal allergens

Fungi, such as mould can release large amounts of allergenic spores into the indoor and outdoor environments. Outdoor moulds can be present in all conditions, with seasonal peaks in hot and humid conditions, while indoor moulds are associated with dampness. They are particularly plentiful in bathrooms and kitchens.

Occupational exposures

Occupational irritants can cause and worsen the symptoms of hay fever. They include different forms such as fumes, dust, vapours and gases, or different types such as chlorine or wood dust.

Common allergens in the workplace can include natural latex rubber (made using a water-soluble protein obtained from a particular rubber tree), bakery allergens such as wheat, enzymes and mites that may be in stored cereal, while people working in fish/seafood processing plants can become sensitised from breathing fish/crustacean proteins in. Scientists in cleaning product companies can also sensitise to the enzymes contained in products such as washing powder, while laboratory workers can sensitise to rats and mice.

The correct treatments can be effective in reducing your symptoms. You should seek advice from your doctor or a pharmacist about which medicines or treatments will relieve your particular symptoms based on their severity.

Not sure what to do next?

If you are still concerned about your hay fever, check your symptoms with healthdirect’s online Symptom Checker to get advice on when to seek medical attention.

The Symptom Checker guides you to the next appropriate healthcare steps, whether it’s self care, talking to a health professional, going to a hospital or calling triple zero (000).

Last reviewed: July 2017

Need more information?

These trusted information partners have more on this topic.

Top results

Allergic rhinitis - hay fever -

Rhinitis means inflammation of the lining of the nose. Allergic rhinitis means that this inflammation is caused by an allergy.

Read more on myDr website

Hayfever (seasonal rhinitis; allergy) information | myVMC

Seasonal rhinitis or hay fever is an exaggerated response to an allergen (e.g. pollen), causing inflammation of the nose, itchy eyes and sneezing.

Read more on myVMC – Virtual Medical Centre website

Allergy and immune system information | myVMC

Allergies including hay fever (allergic rhinitis) are caused by an overactive immune response, which can cause symptoms from a runny nose to anaphylaxis.

Read more on myVMC – Virtual Medical Centre website

What else could it be? - An Asthma Australia site

There are other conditions that have similar symptoms to asthma, or that are common in people who have asthma:

Read more on Asthma Australia website

Hay fever in children and teenagers | Raising Children Network

Hay fever is an allergy. Hay fever symptoms include a runny nose, itchy eyes and sneezing. See a GP about your childs symptoms and hay fever treatment.

Read more on website

Hay fever (allergic rhinitis)

Allergic rhinitis (hay fever) is an allergic reaction to pollens, dust mite, moulds and animal hair.

Read more on WA Health website

Asthma and hay fever - An Asthma Australia site

asthma and hay fever

Read more on Asthma Australia website

Hay fever treatments -

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.

Read more on myDr website

Hay fever | National Centre for Farmer Health

Hay fever is an allergic reaction to environmental allergens. It is very common and often occurs during spring. Read more...

Read more on National Centre for Farmer Health website

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. Up to four

Read more on National Asthma Council Australia website

Healthdirect 24hr 7 days a week hotline

24 hour health advice you can count on

1800 022 222

Government Accredited with over 140 information partners

We are a government-funded service, providing quality, approved health information and advice

Australian Government, health department logo ACT Government logo New South Wales government, health department logo Northen Territory Government logo Government of South Australia, health department logo Tasmanian government logo Government of Western Australia, health department logo