Can seasonal allergies make you feel sick?

Overview

Do you ever feel tired, run-down, or like you’ve caught a cold — only to realise it’s your allergies acting up? It’s completely real. Seasonal allergies can make you feel unwell, not just sneezy and itchy. In fact, seasonal allergies affect up to 30% of Australians¹.

Let’s explore why allergies cause these symptoms and what you can do to feel better.

What are seasonal allergies?

Seasonal allergies, also known as hay fever or allergic rhinitis, occur when your immune system reacts to harmless particles in the air. Common Australian triggers include:

• Grass and tree pollen (especially in spring and summer)
• Dust and mould during humid seasons
• Certain weeds, such as ryegrass and wattle, which release large amounts of pollen

Hay fever is an immune reaction, not an infection².

Can seasonal allergies make you sick?

Yes, seasonal allergies can mimic cold or flu-like symptoms, making you feel under the weather. When your immune system reacts to allergens, it releases histamine, which causes swelling, fatigue, nasal blockage, and an overall “off” feeling.

Ongoing sneezing, sinus pressure, and poor sleep can worsen these symptoms, making allergies feel very similar to being sick.

Symptoms

Common symptoms of seasonal allergies include:

• Runny or blocked nose
• Sneezing
• Itchy or watery eyes
• Fatigue or ongoing tiredness
• Headaches or sinus pressure
• Mild sore throat caused by post-nasal drip
• Difficulty concentrating (“allergy fog”)
• Occasional coughing or wheezing, especially if you have asthma

Tip: Allergies do not cause fever — this is a key difference between allergies and viral infections.

Why allergies cause fatigue and sickness-like feelings

Allergies can leave you feeling unusually tired and unwell because your immune system is working overtime, even though there is no real threat.

1. Immune overreaction: Your body releases histamine and other inflammatory chemicals, which can leave you feeling drained and low on energy.
2. Blocked sinuses: Congestion and sinus pressure restrict airflow and can cause a heavy-headed feeling.
3. Poor sleep: Night-time sneezing and nasal congestion can disrupt sleep, leading to daytime fatigue.
4. Dehydration: A runny nose and mouth breathing may cause mild dehydration, which can worsen tiredness.

Allergies vs Cold

Allergies and colds often share similar symptoms, which can make it hard to tell them apart. The table below highlights the key differences:

If you’re unsure, consult an online GP — especially if symptoms last longer than expected.

Allergy Relief Tips

While allergies can leave you feeling drained, simple everyday strategies can help you breathe easier and feel more like yourself. Here are a few practical tips:

• Take antihistamines or nasal sprays as directed.
• Use saline rinses to clear nasal passages.
• Stay hydrated and get adequate rest.
• Keep windows closed during high-pollen days.
• Use air purifiers indoors.
• Avoid early mornings or windy outdoor activities, when pollen levels peak.
• Keep track of local pollen counts.

When to see a GP

You should see a GP if:

• Over-the-counter treatments don’t provide relief.
• Symptoms worsen or lead to sinus infections.
• You have asthma or breathing difficulties triggered by allergies.
• You’re unsure whether symptoms are due to allergies or illness.

How Hola Health can help

If you’re struggling with persistent allergy symptoms, Hola Health makes it easy to access expert care online with tailored treatment options.

• Get online telehealth consultations for allergy diagnosis and management.
• Get prescriptions for antihistamines, nasal sprays, or other allergy relief via eScript.
• Receive personalised allergy management plans based on your triggers and symptoms.
• Access care from anywhere in Australia — no waiting rooms or travel required.

Conclusion

Seasonal allergies can make you feel sick, even though they aren’t caused by an infection. With proper care and consistent management, symptoms can be controlled effectively. If allergies are making you feel constantly unwell, speak with a Hola Health GP online for expert advice and appropriate treatment options.

FAQs

Why do allergies make me feel tired?

Allergies can cause fatigue because your immune system is working overtime, and ongoing inflammation can drain your energy levels.

Can allergies cause body aches or a sore throat?

Allergies may cause mild throat irritation due to post-nasal drip, but body aches are less common and usually suggest an infection.

How can I tell if it’s a cold or allergies?

If you develop a fever, notice thick or discoloured mucus, or experience a sudden onset of symptoms, these are more likely signs of an infection.

Can allergies trigger asthma or sinus infections?

Yes. Untreated allergies can worsen asthma symptoms and increase the risk of sinus congestion or infections.

How can I prevent allergies during spring in Australia?

Stay indoors on high pollen days, keep windows closed, shower after outdoor exposure, and use prescribed allergy treatments consistently.