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Symptoms

Spotting the symptoms of flu

It is easy to mistake flu for a bad cold. But flu can be serious, so it is important to learn how to spot the symptoms.

Flu symptoms usually appear 2-3 days after catching the virus. [1] They strike suddenly (within 3-6 hours) and, as a result, people often describe feeling "like they have been hit by a bus".
So what are the most common symptoms of flu? Know your flu FACTS

  • Fever
  • Aches
  • Cough
  • Tiredness
  • Sudden symptoms.

Symptoms of flu differ from the common cold. Learn how to tell the difference.

Flu symptoms may last for as long as 2-3 weeks. They can be mild or severe - and if they're mild can become severe without much notice. Be aware of your body and monitor your body temperature. Remember, you will get the most benefit from prescription antivirals if you start taking them within 48 hours of symptoms first appearing, so act quickly.

                        

 

Spotting the symptoms of flu in children

Lots of children get flu; however, it can be a difficult illness to recognise in very young children as they can find it hard to describe their symptoms. [2] Also, flu can be easily confused with other childhood infections.

In addition to the symptoms described above, children with flu often have a runny nose and stomach problems, with nausea, vomiting, and diarrhoea. To find out more about flu in children, click here.

Think you have flu?

If you think you or a family member has flu, it's important to act fast! By acting within 48 hours of symptoms appearing, flu can be beaten with antiviral treatments available only on prescription from your doctor.

To view a short film about flu symptoms and how to recognise them, follow the link.

 

  1. Nicholson K. Human influenza. In: Nicholson K, Webster RG, Hay A, eds. Textbook of influenza. Oxford, UK: Blackwell Science, 1998: 219–64.
  2. Peltola V, Reunanen T, Ziegler T, Silvennoinen H, Heikkinen T. Accuracy of clinical diagnosis of influenza in outpatient children. Clin Infect Dis 2005; 41: 1198–200.
  • "I would describe flu as something that makes you feel very, very ill. You get a headache, aching bones, and are generally fed up"
  • "When I get flu symptoms I feel like a train has run over me"
  • "I felt very sick and, during the first week, I had high temperature. Flu was very different to a cold. I went back to work after two and a half weeks. Then I suffered a setback for another week"
  • "I run a guesthouse; flu would be a real pest for me. I couldn’t cook, I shouldn’t cook, and I wouldn’t cook, so I would need to get a lot of extra help in. It would cost me a lot more money. So flu’s a real problem, a right downturn"
  • "I work on my own and when I can’t work, I have to try not to infect my little children, so they avoid getting the flu as well"
  • "I feel a little numb, like I’m in another dimension. Because in general I have sore throat, headache, I feel all clogged-up. Usually a sensation like I’m floating in the air"
  • "Shivers, sweats, makes you ache. Last time I had flu I was off for two weeks"
  • "I think that I would probably be concerned that I would pass flu onto my children, who might not be able to deal with it as well as I would"
  • "Flu makes you feel like you’ve been hit over the head with a baseball bat. You don’t feel like you can get yourself out of bed as all your energy is drawn from you"
  • "I was incapable of working. It just wasn’t possible at all… and my flu dragged on for more than a week"
  • "I have no strength. It annoys me because I can do nothing, it seems like I’m wasting my time"
  • "Flu’s like being hit by a truck because you feel completely gone. There is no energy left in your body. You are suffering from high temperature. You’re sweating a lot and you feel really unwell"
  • "First of all infinite tiredness, then I feel like sleeping and don’t want to eat"
  • "I felt really miserable because my muscles and my bones were aching. Well, I can hardly describe it, I just felt really awful, absolutely miserable"
  • "It’s like there’s something huge treading on your head, like a deafening noise that destroys the eardrums"
  • "The fever was constantly rising – I immediately measured my temperature as soon as I got home. It was 41°C and it kept rising and I was wondering what’s going on. I was really scared! Everything was hurting and it all happened so fast. Flu came out of the blue"
  • "I always feel like my limbs have iron weights tied to them and I’m going to fall over any minute, a really stuffy runny nose and feel antisocial"
  • "I was totally dependent on others! I was incapable of doing anything at all"
  • "The real flu knocks you for six – you just don’t want to move or do anything. It’s not very nice"
  • "Not being able to go to work. Not being able to do the things I have to do at home and the commitments that I have day by day"