The facts about colds and flu

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Making sure your cold and flu knowledge is up to date is important to keeping yourself healthy. See what the key differences are and facts about each.

Young woman standing in a field outside at sunrise in cold weather
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What is the difference between a cold and a flu?

Colds and flu are both viral respiratory illnesses, but even though they can cause similar symptoms – things like a cough, a sore throat and feeling tired – they’re caused by different viruses. In fact there are over 200 different viruses that can cause the common cold

Still not sure how a cold and flu are different or if one can turn into the other? Here’s what you need to know – and how to work out which one you’ve got if you get sick.

While an illness that initially seems like a cold can turn out to be the flu,  a cold can’t turn into the flu – or vice versa  – because colds and flu are caused by different viruses.

And that’s good news: the symptoms of a common cold are typically less severe and don’t last as long, so if you do have a cold, you’ll feel better sooner. Symptoms usually peak within two or three days of catching a cold, although some symptoms, particularly a runny or blocked nose, can last for up to 10 to 14 days.

In fact, a cold-related cough can linger for as long as three weeks . The vast majority of colds get better without any specific treatment , but if any symptom is severe or concerning, or symptoms last for more than 10 days without any improvement, you should see a doctor

What are the symptoms and stages of a cold?

The most common symptoms of a cold are:
  • A runny nose or nasal congestion
  • Sneezing
  • A sore throat
  • A mild or moderate cough
  • Mild fatigue
Unlike the flu, a cold rarely causes fever, headache, aches and pains, nausea or vomiting.

As mentioned above, cold symptoms usually start two or three days after you’ve been exposed to the cold-causing virus, and you’re most contagious for the first three or four days after symptoms begin. From there, most colds clear up within a week, although some symptoms can hang around for two or even three weeks.

What should I eat when I have a cold?

The first thing to know is that, despite the age-old wives’ tale, you don’t have to ‘feed a cold and starve a fever’. Instead, just eat when you’re hungry, bearing in mind that you may have less appetite when your immune system is fighting a cold.

While there’s no cure for the common cold, symptoms can be relieved by, for instance, sucking lozenges and drinking plenty of fluids, and it can pay to bump up your intake of foods that support your immune system, including whipping up a batch of warming broccoli and basil soup that’s jam-packed with green goodness.

Warm drinks and liquids can also help to ease a sore throat and a dry mouth caused by a cold.

Fact vs fiction - 5 cold and flu myths, busted

Confused about how you can catch a cold or flu, whether you can cure it and how likely you are to pass it on to someone else if you do get sick? There’s a fair bit of conflicting information available so if you’re not certain about something, you’re not alone. 

To sort out some important facts from a whole lot of fiction, here’s what you need to know about a handful of common cold and flu myths you may have heard.

Myth 1. You can catch a cold by being cold

False. Colds are caused by viruses, so you have to be exposed to one of the 200-plus cold-causing viruses to catch a cold. 

So why does it seem like there are more colds going around during winter? Not only does research show that cold viruses spread more easily in low temperatures, another reason more people catch colds when the weather is cooler is because we tend to spend more time indoors, in closer proximity to others.

Myth 2. The flu is just a bad cold

No, it’s not. Colds and flu do have some things in common, including sharing a few of the same symptoms , but they also have a lot of differences , like the fact that they’re caused by completely different viruses.  

The thing to remember is that the flu can be much more severe and lasts longer than a cold and, unlike the flu, a cold rarely causes fever, headache, aches and pains, or nausea or vomiting.

Myth 3. If my cold or flu symptoms are mild, I’m less infectious

No – just because your symptoms are mild, it doesn’t mean the virus is mild. 

Your immune system is probably just up to the task of controlling the virus well  – in fact, some people can even become infected with a cold virus and show no symptoms. 

Likewise, up to 30 per cent of people carrying the flu virus have no symptoms. 

So, regardless of how well or unwell you feel when you’re sick, take steps to reduce spreading it, including coughing or sneezing into your elbow or a tissue – and throwing that tissue away immediately. 

Washing your hands regularly and staying at home as soon as you notice symptoms is also important, bearing in mind that you’re most contagious for the first three or four days after symptoms begin.

Myth 4. You can take something to cure a cold

False – there is no cure for the common cold and there isn’t a vaccine, either. Antibiotics aren’t helpful, because they only treat illnesses that are caused by bacteria not viruses, like colds. 

There are things you can do to help relieve cold symptoms though, such as getting plenty of rest and staying hydrated. 

Similarly, while it’s not possible to completely prevent the spread of cold-causing viruses, you can reduce your chances  of getting sick  by adopting some helpful habits and taking measures to support a healthy immune system.

Myth 5. The only way you can catch a cold or flu is by being near someone who has it

No. While the viruses that cause colds and flu do spread through the air and via close personal contact, you don’t have to physically breathe in particles that have been coughed or sneezed out to become infected. 

Given the fact that viruses can survive on some surfaces for up to two days , one of the main ways viruses spread is when someone touches something that has been contaminated with the virus and then touches their face. 

It means frequently washing your hands properly is one of the most powerful things you can do to reduce your risk of catching a cold  or flu this winter.