What causes seasonal allergies and how to manage them

Seasonal allergies occur when the immune system reacts to substances that become more common in the air at particular times of year. Pollen from grasses, trees and weeds is the usual trigger, although mould spores and outdoor dust can also contribute. The result may be sneezing, a blocked or runny nose, itchy eyes, coughing and tiredness.

In Australia, symptoms often follow local weather and vegetation patterns rather than a single nationwide allergy season. Grass pollen can be troublesome during spring and early summer, while warm, windy conditions may spread particles across cities such as Melbourne, Sydney, Brisbane and Perth. Understanding the trigger makes it easier to reduce exposure and choose suitable treatment.

How the immune system reacts to pollen

An allergy begins when the immune system incorrectly identifies a harmless substance as a threat. After exposure, the body releases chemicals including histamine. Histamine widens small blood vessels and stimulates nerve endings, producing familiar symptoms such as nasal congestion, watery eyes, sneezing and an itchy throat.

The first contact with a trigger may cause little obvious discomfort, but repeated exposure can lead to a stronger reaction. This is why a person may feel well during winter and then develop hay fever when grasses flower. Sensitivity can also change over time, so someone who had mild symptoms as a child may experience more noticeable reactions as an adult.

Allergic rhinitis affects the lining of the nose and upper airways. It is different from a common cold, which is caused by a virus and often includes body aches, fever or a sore throat that develops over several days. Allergies usually produce clear nasal discharge, repeated sneezing and itchy eyes, although symptoms can overlap.

Pollen counts are influenced by wind, temperature and rainfall. Dry, windy days can carry grass pollen over long distances, while rain may temporarily clear the air. In parts of Victoria, severe storms during high-pollen periods have been associated with thunderstorm asthma. People with asthma or breathing difficulties should follow their personal action plan and seek urgent help for severe wheezing or shortness of breath.

Common triggers across Australian seasons

Grass pollen is one of the most important causes of hay fever in Australia. It is particularly common from late winter through summer, with exposure often rising in southern states during spring. Trees and weeds can also release allergenic pollen, and the timing differs between regions. A person moving from Adelaide to Cairns may notice a different pattern because of changes in climate and plant life.

Mould is another seasonal trigger. It grows in damp soil, leaf litter, compost, bathrooms and poorly ventilated rooms. Mould spores can increase after rain or flooding, especially when homes remain humid. Keeping indoor spaces dry and addressing water leaks can help reduce this source of irritation.

Outdoor habits can make a difference. Mowing lawns, trimming weeds and playing sport on freshly cut grass may disturb pollen. When possible, delegate mowing during peak symptoms, wear wraparound sunglasses outside and shower after extended outdoor activity. Washing hair before bed can prevent pollen from transferring to pillows and bedding.

Pets may carry pollen indoors on their coats, even when the animal itself is not the original cause of the allergy. Wiping a dog’s coat and paws after a walk, keeping pets away from the bed and vacuuming regularly may reduce exposure. Air conditioning with a clean filter can also be useful, particularly during hot Australian summers when windows are often left open.

Recognising symptoms and checking for other causes

Typical hay fever symptoms include repeated sneezing, an itchy or runny nose, nasal blockage, post-nasal drip, itchy eyes and a dry cough. Some people develop pressure around the cheeks or forehead because congestion affects the sinuses. Poor sleep from nighttime congestion can lead to headaches, low energy and difficulty concentrating at school or work.

Symptoms that occur at the same time each year, worsen outdoors and improve indoors are more suggestive of seasonal allergy. A symptom diary can help identify connections with weather, gardening, travel, pets and particular locations. Local pollen information, weather reports and health alerts can add useful context, although forecasts do not capture every individual trigger.

Colds tend to improve within about one to two weeks, while allergy symptoms may continue for as long as the trigger is present. Irritation from smoke, strong fragrances, cleaning products or air pollution can resemble allergy symptoms without involving pollen. This distinction matters because avoiding irritants and treating an allergic reaction are not always the same.

A general practitioner can assess persistent or severe symptoms and may recommend allergy testing. Testing can identify sensitivity to selected pollens, moulds, dust mites or animal allergens. Medical advice is especially important when symptoms disturb sleep, interfere with daily activities, recur frequently or occur alongside asthma.

Practical ways to reduce exposure

The simplest approach is to limit contact with airborne allergens when levels are high. Keep doors and windows closed during windy periods, use recirculated air in the car and change clothes after outdoor activities. Sunglasses can protect the eyes, while a well-fitted mask may reduce inhalation during gardening or mowing.

Indoor cleaning should focus on practical measures rather than creating more irritants. Vacuuming with a suitable filter, damp-dusting surfaces and washing bedding regularly can reduce dust and pollen. Avoid excessive use of heavily scented sprays, which may aggravate already sensitive nasal passages. Check air conditioner and air purifier filters according to the manufacturer’s instructions.

Saline nasal sprays or rinses can wash mucus and particles from the nose. If using a rinse device, use sterile, distilled or previously boiled and cooled water, and clean the device properly. A pharmacist can explain safe technique and help select an appropriate product for children, adults, pregnancy or other health conditions.

A routine can make prevention easier. Check pollen and weather conditions before commuting, exercising or gardening, and plan outdoor tasks for times when wind is lower. Those who organise busy schedules may also benefit from understanding fixed timetables, such as these stock market hours, when coordinating work, appointments and other daily commitments around symptom-heavy periods.

Medicines and professional care

Pharmacists commonly recommend antihistamines for sneezing, itching and a runny nose. Some newer antihistamines are less sedating than older products, but drowsiness can still occur. Anyone who feels sleepy should avoid driving, operating machinery or combining the medicine with alcohol. Always follow the label and check for interactions with other medicines.

Nasal corticosteroid sprays are often useful for ongoing nasal inflammation and congestion. They generally work best when used regularly and with correct technique rather than only after symptoms become severe. The spray should be directed slightly away from the middle wall of the nose, and a pharmacist or doctor can demonstrate proper use.

Decongestant sprays may provide short-term relief, but prolonged use can cause rebound congestion. Oral decongestants may be unsuitable for people with high blood pressure, heart conditions, glaucoma or certain medication combinations. Australian products are regulated by the Therapeutic Goods Administration, but “over the counter” does not mean every option is appropriate for every person.

Ask a pharmacist about products listed on the Australian market and whether a medicine is suitable for a child, during pregnancy or while breastfeeding. Some treatments may be available through the Pharmaceutical Benefits Scheme in specific circumstances, while others require private purchase. Keeping a record of active ingredients helps prevent accidental duplication across combination cold and allergy products.

See a doctor if symptoms persist despite sensible treatment, if sinus pain becomes intense, or if nasal discharge and fever suggest infection. Seek urgent medical care for swelling of the lips or tongue, difficulty breathing, faintness or a rapidly worsening reaction. For people with asthma, worsening wheeze, chest tightness or trouble speaking in full sentences requires prompt attention.

Building a long-term allergy plan

An effective plan combines trigger reduction, suitable medicine and preparation for the months when symptoms usually peak. Begin before the expected season if a pharmacist or doctor has advised preventive treatment. Waiting until congestion is severe can make symptoms harder to control and may affect sleep for several nights.

Record the dates, location and intensity of symptoms. Note whether the problem followed mowing, a windy day, a storm, house cleaning or time around animals. This information helps a health professional distinguish seasonal allergic rhinitis from asthma, chronic sinus disease, medication effects or another condition.

Families should explain allergy routines to children, schools and carers. A child may need access to prescribed medicine, tissues, water or an asthma action plan during outdoor activities. Schools and workplaces can often reduce exposure by moving activities indoors during extreme pollen or thunderstorm conditions, although individual arrangements should be discussed in advance.

Stress and poor sleep do not create a pollen allergy, but they can make symptoms feel harder to manage. Regular sleep, hydration, moderate exercise in low-pollen settings and sensible breaks can support general wellbeing. When symptoms make concentration difficult, avoid making important decisions while tired; even recreational activities that rely on careful observation, such as practising poker bluffing techniques, are better approached when medication side effects and fatigue are under control.

Start by identifying the season, place and activity most closely linked with your symptoms. Check local conditions, reduce exposure where practical and speak with an Australian pharmacist or GP about safe treatment. Promptly address breathing problems or severe reactions, and keep a written plan available during the months when pollen and mould are most active.