13th February 2024

Cold vs Flu: What is the Difference?

With the transition of seasons, the inevitable arrival of cold and flu viruses loom, leaving many of us wondering whether that sniffle is just the common cold or a more serious bout of the flu. While both are respiratory illnesses caused by viruses, understanding the differences in symptoms is crucial for timely and effective management to aid swifter recovery.

Gillian Barrett, Occupational Health Nurse at Mater Private Network in Cork, helped us put together the below information to highlight the difference between the common cold and flu, and to help you navigate through these seasonal health challenges. 

Onset and severity

Common cold: symptoms of a common cold typically develop gradually and are milder compared to the flu. Sneezing, a runny or stuffy nose, and a scratchy throat are common initial signs.

Flu: in contrast, the flu tends to strike suddenly and with more intensity. Symptoms include fever, body aches, chills, and extreme fatigue. The onset of the flu can be rapid and severe.


Common cold: fever is uncommon in adults with a common cold. If present, it is usually mild.

Flu: fever is a key symptom of the flu and is often one of the first signs to appear. Temperatures can range from moderate to high, contributing to the overall feeling of being unwell.

Respiratory symptoms

Common cold: respiratory symptoms primarily involve a runny or stuffy nose, sneezing, and a mild cough. A sore throat is also common.

Flu: respiratory symptoms are more severe with the flu, including a dry cough, very sore throat, and sometimes shortness of breath. In some cases, the flu can progress to pneumonia or bronchitis.

Body aches and fatigue

Common cold: while some mild fatigue may be present, body aches are generally mild and localised.

Flu: intense fatigue and widespread body aches are characteristic of the flu. Even simple tasks can become exhausting when you have the flu.


Common cold: headaches are occasional and usually mild with a common cold.

Flu: headaches are common and can be severe with the flu, often accompanied by the general feeling of heaviness and discomfort.

While the common cold and flu share similarities, key differences in symptoms can help you to distinguish between the two. Recognising whether you're dealing with a common cold, or the flu is crucial for seeking appropriate medical care and preventing the spread of these viruses. As always, practicing good hygiene, getting vaccinated, and maintaining a healthy lifestyle can go a long way in minimising the impact of these seasonal respiratory infections.

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Mater Private Network offers respiratory medicine services in both our Dublin and Cork hospitals. Our dedicated team of world class respiratory consultants offers a complete range of tests and treatments for lung related conditions.

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