Symptoms of influenza

Overview

Each year in Australia, numerous individuals fall ill with the flu, often mistaking the initial signs for a typical cold. Influenza is a highly infectious viral illness that impacts the respiratory system, including the nose, throat, and lungs. Identifying symptoms promptly is crucial for preventing complications and minimising the spread, especially during Australia's peak flu season. Being aware of what to recognise enables you to take swift action and recover more efficiently. Note: Some respiratory symptoms may require an in-person physical examination or diagnostic testing that cannot be performed via telehealth.

What Is Influenza (Flu)?

Influenza, often referred to as the flu, is a viral infection that transmits through droplets released when an infected individual coughs, sneezes, or speaks. In contrast to a cold, flu symptoms emerge abruptly and are generally more intense. The peak flu season in Australia occurs from May to September. Groups at higher risk include:

• Elderly individuals
• Those with chronic health conditions
• Pregnant individuals
• Indigenous Australians and Torres Strait Islander peoples

Why Early Flu Detection Matters

Influenza A, widely referred to as the flu, can strike swiftly, leaving you feeling exhausted within hours. Recognising early indicators such as fever, chills, and body pain can enable you to act quickly, minimising symptom severity and speeding up recovery. Being aware of initial symptoms also helps prevent the spread of the virus to others, seek medical attention early either from a physical doctor or an online doctor particularly during peak flu season. Early detection of influenza can enhance the effectiveness of management, especially for children, pregnant individuals, and the elderly. Prompt antiviral management and adequate rest can considerably reduce recovery time and decrease the likelihood of complications. Timely recognition of symptoms also helps to contain the virus's spread to family members, coworkers, and others around you.

How Influenza A spreads

The influenza virus transmits easily through droplets when someone infected coughs, sneezes, or even speaks. These droplets can remain on surfaces for up to 48 hours, meaning that touching shared items like doorknobs or phones can facilitate the spread of infection. Maintaining good hand hygiene and wearing masks in crowded settings can lessen your chances of contracting or transmitting the flu.

Common symptoms

Common flu symptoms typically arise suddenly and can include:

• High fever or chills, typically highly pronounced and develop rapidly
• Dry and persistent cough, occasionally severe
• Sore throat
• Nasal congestion or runniness
• Headache, often more intense than what is experienced with a cold
• Fatigue and muscle aches can linger for several weeks
• Sweating and shivering
• Decreased appetite

In contrast to COVID-19, losing taste and smell is not as prevalent with the flu. Less frequent symptoms include:

• Nausea or vomiting (more common in children)

In contrast to a cold, flu symptoms emerge rapidly and generally start with fever and fatigue rather than a gradual onset of congestion.

How quickly do symptoms appear?

Following exposure to the influenza A virus, symptoms usually develop within 1 to 4 days, most commonly around the two-day mark. You might feel completely healthy one moment and then abruptly feel fever, chills, and body aches. This swift onset sets influenza A apart from the typical cold, which progresses more gradually. It is essential to recognise that you can still transmit the flu before symptoms manifest, which is why early awareness and prevention are vital.

Serious symptoms

Seek immediate medical assistance if you experience:

• Difficulty breathing or rapid breathing
• Chest pain or a feeling of tightness
• A persistent high fever (39°C or more)
• Confusion, lightheadedness, or fainting
• Bluish colouration of the lips or face
• Extreme weakness or signs of dehydration
• Continuous vomiting, dehydration, or dizziness
• Symptoms that persist for more than 5–7 days without improvement

If symptoms are severe, dial 000 or proceed to the nearest emergency department. Dial 000 if you experience sudden shortness of breath, chest tightness, or bluish lips. If you are pregnant, over 65, or have chronic conditions like asthma, or heart issues, reach out to a doctor as soon as symptoms arise.

Flu symptoms vs common cold

Symptom	Cold	Flu
Onset	Gradual	Sudden
Fever	Rare	Common, often high
Body aches	Mild	Common, often severe
Fatigue	Mild	Moderate to severe
Headache	Mild	Common
Complications	Rare	More likely

Timeline of flu symptoms

Days	What to expect
1-3	Sudden fever, chills, body aches, headache, sore throat
3-5	Peak symptoms: fatigue, cough, nasal congestion
5-7	Fever improves, cough and tiredness may continue
1-2 weeks	Recovery phase – fatigue may linger

Some people, especially older adults or those with chronic illnesses, may take longer to recover.

What to Do When Flu Symptoms Start

If you suspect you are coming down with the flu, acting promptly can facilitate a smoother recovery. Here's what you can do at home:

• Rest and recuperate: Allow your body the necessary time to heal.
• Hydrate well: Consume plenty of water, herbal tea, or soups to maintain hydration.
• Monitor your symptoms: Keep a close eye on how you're feeling; worsening symptoms may necessitate medical attention.
• Prevent the spread of germs: Remain at home, cover your mouth when coughing, and wash your hands frequently.
• Consult a doctor promptly: Consulting a practitioner early allows for a clinical assessment and prescription medication options, if clinically appropriate.

When to see a doctor

You should pursue medical advice if:

• You have a persistent high fever that does not improve after three days
• You experience problems with breathing or chest pain
• You feel overwhelming fatigue or signs of dehydration
• Symptoms deteriorate after an initial period of improvement
• You belong to a group at higher risk

While telehealth is a convenient option for many, some patients with worsening respiratory symptoms may require an in-person assessment or emergency care.

How Hola Health can help

Hola Health is an Australian telehealth platform that connects you with registered doctors and nurse practitioners — from the comfort of your home, at a time that suits you. Depending on your situation, a Hola Health clinician may be able to help with:

• Flu assessments available online or in-person
• Access to diagnostic requests (if clinically appropriate)
• Flu vaccination services
• Convenient telehealth appointment scheduling
• 24/7 General medical advice via online doctor consult — talk through symptoms or health concerns with a registered doctor or medical practitioner
• Online doctors certificate — for work or personal leave, when clinically appropriate
• Referrals to specialists - or in-person services when needed
• Online prescriptions — at a clinician's discretion and where clinically suitable

Hola Health clinicians are AHPRA-registered Doctors and medical practitioners in Australia. They will always recommend an in-person consultation, specialist referral, or emergency care if that is in your best interest. Note: Telehealth is not suitable for all conditions. Hola Health does not replace your regular GP, specialist, or emergency services. If you are unsure whether telehealth is right for your situation, we recommend speaking with your usual healthcare provider. In emergencies, call 000.

Conclusion

Flu symptoms manifest suddenly and are typically more intense than those of a cold. Early detection, adequate rest, and medical support can help prevent complications and safeguard those around you. Staying informed and getting vaccinated annually are essential measures to help prevent the flu. Recognising early flu symptoms enables you to act swiftly, recover more quickly, and lessen the risk of transmitting the virus to others. If you begin to feel feverish, fatigued, or achy, don't hesitate; schedule a telehealth consultation with Hola Health. Australian doctors are available every day of the week to provide a clinical assessment and management advice from the comfort of your home.

FAQs

What are the initial indications of the flu?

Rapid fever, chills, headaches, sore throat, and fatigue are early indicators of influenza.

How do flu symptoms compare to a cold?

Flu symptoms occur suddenly and are more intense, featuring higher fever and more pronounced body aches than a cold.

How long does the flu typically last in adults?

Most individuals recover within 7 to 10 days, although fatigue can persist for up to two weeks.

Can a person have the flu without experiencing a fever?

Yes, some individuals, particularly older adults, might have mild or no fever but still exhibit other flu symptoms.

What temperature qualifies as a high fever with the flu?

A fever reaching 39°C or above is deemed high and may require medical attention.

When should I consult a doctor regarding flu symptoms?

If symptoms worsen, last longer than a week, or if you experience chest pain, shortness of breath, or dehydration.

Is the flu infectious?

Yes, it easily spreads through respiratory droplets and can be contagious one day before the onset of symptoms and up to five days thereafter.

How can I differentiate between the flu and COVID-19?

The flu typically has a rapid onset of symptoms, whereas COVID-19 often includes loss of taste or smell. Testing is necessary for accurate diagnosis.

What are the indicators of severe flu symptoms?

Signs of severe flu include difficulty breathing, chest pain, confusion, and a persistent high fever.

How quickly does the flu onset occur?

Influenza A generally appears suddenly, and symptoms usually develop within 1–4 days after contact, most often around 48 hours.