When the temperature drops, sniffles start and winter becomes prime time for colds, flus and a whole lineup of respiratory illnesses. It’s the season of snotty tissues, steamy soups and sick days. Not all winter bugs are created equal, in this guide, we’ll break down the most common winter illnesses, highlight key signs and symptoms to watch out for and share practical tips to help ease the severity if illness strikes.
If you’re coughing and sneezing this winter, staying informed is your first defence, a little know-how can go a long way towards keeping you and your family well through the colder months where colds and flus are more common. People are indoors more often allowing viruses to pass more easily from one person to another. How do you know if you have a cold or something more serious? Will you need antibiotics? Are you contagious? When is it safe to return to school or work? Our Winter Illness guide can help answer these questions!
The Common Cold – A Seasonal Nuisance
What is it? The common cold is a mild viral infection that affects the nose, throat and sinuses.
Symptoms: It causes symptoms like a runny nose, sore throat, a low-grade fever, fatigue, chills, aches, sneezing and coughing which usually clears up on its own within a week or two.
How the Common Cold Spreads: Somebody coughed or sneezed near you, or you touched a contaminated surface like a doorknob. More than 200 viruses can cause colds. The most common is the rhinovirus.
What should you do? There’s no real cure for the common cold. Paracetamol, decongestants, throat lozenges and antihistamines can help with symptoms. Your body needs rest and hydration to help speed up your recovery. Strengthen your immune system with vitamin C, zinc, and a balanced diet.
Returning to work or school? Most people are contagious for about a week starting the day before they have symptoms. If you feel well enough to attend school or continue working, wash your hands frequently and avoid close contact with others especially if you are still coughing and sneezing.
How common is it? Very. Of all illnesses, common colds are blamed for the most days off work or school and the most visits to health care practitioners.
When to See a doctor if: Symptoms linger beyond a few days or get worse, or if new symptoms develop.
Influenza (flu) – A More Serious Threat
What is it? Influenza or the flu is a contagious viral infection that hits suddenly with symptoms like fever, chills, body aches, fatigue and cough. It’s more severe than a cold and can lead to serious complications, especially in vulnerable groups.
Symptoms: It causes symptoms like exhaustion, fever, headache and body aches, sneezing, coughing and a possible sore throat. The worst symptoms (fever and body aches) are often over in 3-5 days. The coughing and general fatigue can linger for 2 weeks or more.
How the Flu Spreads: The influenza (flu) virus is spread from airborne droplets sneezed or coughed or by touching contaminated surfaces. Flu viruses keep evolving which is why flu vaccine is updated each year.
What should you do? Relieve symptoms with rest, fluids and over-the-counter Cold & Flu or herbal treatments. Eat nutritious foods and stay hydrated to support your immune system. In severe cases antiviral medications may be prescribed by your doctor. Antivirals are most effective when started within 48 hours to reduce the flu’s duration, severity and risk of complications.
Returning to work or school? Wait at least five days after onset of symptoms and 24 hours after your fever breaks.
How common is it? Influenza affects a significant number of Australians each year. For instance, in 2024 there were 364,894 reported cases, marking a substantial increase from previous years. By the end of March 2025, over 46,300 cases of influenza have already been recorded indicating an early and active flu season. These figures highlight the importance of annual flu vaccinations and preventive measures to reduce the impact of influenza nationwide
What is the difference between the common cold and influenza? The common cold is milder, with gradual symptoms like a runny nose and sore throat. Influenza (flu) comes on suddenly with more severe symptoms like high fever, body aches and fatigue. Flu can lead to serious complications; colds usually don’t.
See a doctor if: Symptoms get worse, particularly a worsening cough after the first week or if you have a condition that makes you vulnerable to flu complications.
COVID-19– A Continuing Concern
What is it? COVID-19 is a contagious respiratory illness caused by the coronavirus SARS-CoV-2.
Symptoms: It can range from mild symptoms like cough and fever to a severe illness. Some people with COVID have no symptoms at all while others have a sore throat, congestion and cough or runny nose and fever or chills. You may lose your sense of smell or taste, and experience shortness of breath or body aches. Upset stomach, diarrhea or vomiting are also possible.
How long will it last? Acute COVID can hang on for a week or two for mild or moderate cases, longer for severe infections. Post-COVID symptoms, such as lingering cough, on-and-off fever, fatigue, memory issues and changes to your senses of smell or taste, can persist for weeks or even months.
What should you do? If you have COVID stay at home, rest, stay hydrated and manage symptoms with over-the-counter meds. Avoid contact with others especially high-risk people until you are symptom-free. Wear a mask in crowded places and practice good hand hygiene.
Stay up to date with COVID vaccinations as they help prevent serious illness and reduce the spread.
How COVID-19 Spreads: It spreads through close person-to-person contact or spreads through droplets when an infected person coughs, sneezes or talks. Staying up to date on vaccinations, washing your hands, covering your mouth when you sneeze or cough and wearing a mask if you are sick helps avoid getting or spreading COVID-19, which can be dangerous, particularly to those with a weakened immune system.
Returning to work or school? In Australia, while there are no mandatory isolation requirements for individuals who test positive for COVID-19, health authorities strongly recommend staying home until your acute symptoms have resolved to minimise the risk of transmitting the virus to others.
Returning to Work:
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- General Workplaces: It's advisable to remain at home until you are symptom-free. Communicate with your employer about your situation; they may have specific policies regarding returning to work after a COVID-19 infection.
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- High-Risk Settings: If you work in environments such as healthcare, disability or aged care facilities, it's recommended to stay away from the workplace for at least 7 days and until you have no symptoms. This precaution helps protect vulnerable individuals in these settings.
Returning to School: Students and staff should stay home when unwell and only return to school once they are symptom-free. This practice helps prevent the spread of COVID-19 within educational institutions.
It's important to note that guidelines may vary by state and territory, so it's advisable to consult local health authorities or your employer for region-specific advice.
How common is it? COVID-19 is contagious and common. COVID outbreaks tend to occur in waves, often associated with new variants of the coronavirus and the colder winter months when people gather indoors.
See a doctor if: You have difficulty breathing, persistent pain or pressure in the chest, new confusion, inability to wake up or stay awake or bluish lips or face.
RSV (Respiratory Syncytial Virus) – A Risk for Infants & Seniors
What is it? RSV is a viral infection that can lead to inflammation of the respiratory tract and lungs. In children younger than 1 year old, RSV is the most common respiratory cause for hospital admissions.
Who is most at risk of severe RSV infection? Infants (especially those born premature), children, older adults, people with heart and/or lung problems and people with weakened immune systems. RSV vaccines are available for children under the age of 2, adults aged 60 and over and people in the third trimester of pregnancy. The vaccine can help protect against serious RSV illness and hospitalisation, particularly for infants and older adults.
Symptoms: Your child will feel like they have a cold. They may experience a runny nose, coughing, sneezing, wheezing, a decreased appetite and low fever. Most children and adults with RSV will recover in one to two weeks.
How common is it? RSV is very common in Australia especially among young children. Most kids catch it by the age of two. It’s a leading cause of hospitalisation in infants particularly those under 6 months. RSV spreads most in Autumn and Winter with cases peaking between April and July.
How RSV spreads: Your child could become infected by contacting fluids from an infected friend’s nose or mouth. Outbreaks often occur in classrooms, community centres and childcare centres.
What should you do? Wash hands frequently and avoid close contact with sick individuals. Disinfect commonly touched surfaces, especially in homes with infants or elderly individuals.
Caring for someone with RSV: Care for a child with RSV by keeping them comfortable, offering plenty of fluids and using saline drops or a humidifier to ease breathing. Monitor for breathing difficulties or signs of dehydration.
Returning to work or school? You or your child can return 3 - 8 days after first exposure to the virus. However, if an infant or someone with a weak immune system contracts the disease, they may be contagious for up to four weeks.
See a doctor if: You or your child experiences a high fever, a bad cough, wheezing, laboured breathing and/or decreased appetite.
Bronchitis – The Lingering Cough
What is it? Bronchitis can come in two forms, acute = sudden + short-lived or chronic = long-term + recurring.
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- Acute bronchitis is short-term inflammation of the airways resulting in too much mucus, usually caused by a viral infection. It lasts a few days to a few weeks and often follows a cold or flu.
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- Chronic bronchitis is long-term inflammation, defined by a productive cough lasting at least 3 months per year for 2 consecutive years, usually due to smoking or long-term irritant exposure.
Symptoms: Consistent coughing plus chest discomfort and difficulty breathing. A dry cough that becomes mucus-producing. Aches and pains, chills, headache, runny nose, sore throat, shortness of breath, watery eyes and wheezing.
How Bronchitis spreads: from a cold or flu virus therefore, a flu shot lowers your risk or you might have inhaled bacteria. You’re particularly susceptible if you smoke or have allergies, sinusitis, or enlarged tonsils or adenoids.
What should you do? Acute bronchitis will clear up on its own unless it progresses to pneumonia, which can be treated with antibiotics. Meanwhile, a humidifier, cough medicine and pain relievers can ease your symptoms. With chronic the goal of treatment is to reduce symptoms so you can breathe more easily. If you smoke, quitting is recommended.
Returning to work or school? Bronchitis is not contagious once the initial viral phase subsides after a few days, return to work or school when you feel strong enough.
How common is it? both acute and chronic bronchitis are significant health concerns in, acute bronchitis appears to be more commonly encountered, whereas chronic bronchitis (as part of COPD) affects a smaller, though still substantial, segment of the population, particularly among older adults.
See a doctor if: Symptoms don’t improve, or if they get worse or if you have a cough that lasts more than three weeks, produces bloody or discoloured mucus, or is paired with a fever. Early treatment decreases the risk of lung damage.
Pneumonia – A Serious Lung Infection
What is it? Pneumonia is an infection that inflames the air sacs (alveoli) in one or both lungs. The sacs may fill with pus or fluid.
Symptoms: Symptom severity ranges from mild to life-threatening and can include confusion, fever, a cough that produces mucus, heavy sweating, shaking chills, lack of appetite, rapid breathing and pulse, shortness of breath that gets worse with activity and stabbing pain in the chest that’s worse with coughing or deep breathing. Most people respond well to treatment and recover in one to three weeks, but pneumonia can be very serious and even deadly.
How Pneumonia spreads: Viruses are responsible for about one-third of cases. The rest are caused by bacteria or fungi that are inhaled, particularly by people weakened by surgery, illness, age or smoking. Seasonal influenza, respiratory syncytial virus (RSV) and the virus that causes COVID-19 are common causes of pneumonia. Being up to date on your recommended vaccines can help prevent pneumonia.
What should you do? Get vaccinated if you’re at higher risk (elderly, immunocompromised individuals). Rest, eat well and drink plenty of fluids. Bacterial pneumonia can be treated with antibiotics. In both cases, medications can ease your fever and cough.
Returning to work or school? If you have bacterial pneumonia, the risk of infecting others dramatically reduces two days after taking antibiotics. Viral pneumonia is less contagious but avoid others if you have a fever. The more rest the better, don’t rush back give your body time to recover.
How common is it? Pneumonia is very common, especially in children and older adults.
See a doctor if: Your cough gets worse or doesn’t improve, you cough up mucus, you have a persistent fever higher than 38°C, you have shaking chills, or breathing makes your chest hurt. Don’t delay seeing a doctor if you have underlying health conditions, such as heart or lung problems.
Whooping Cough – A Persistent & Dangerous Cough
What is it? Also known as pertussis, whooping cough is a serious and very contagious bacterial infection that mainly affects infants and young children. Whooping cough is also known as the 100-day cough!
Symptoms: It starts like a common cold and progresses to include coughing spells that end with a whooping sound as you gulp for air. Other symptoms include fever, sneezing, runny nose and watery eyes. Whooping cough can last up to 10 weeks. It can lead to pneumonia and other complications.
How did I get it? A bacterium called Bordetella pertussis, which is spread by coughing, sneezing and even breathing which causes whooping cough.
What should you do? Ensure vaccinations are up to date, especially for infants and caregivers. If infected, take prescribed antibiotics and follow isolation guidelines. Stay warm, drink lots of fluids and limit exposure to things that make you cough, like smoke or dust. Ensure your whooping cough vaccinations are up to date.
Returning to work or school? Avoid contact with others until you have been treated with antibiotics for five days.
How common is it? Whooping cough is experiencing a surge in Australia, with the 2024 outbreak being the highest on record surpassing previous peaks and causing significant public health concerns.
See a doctor if: You suspect you have whooping cough.