Symptoms of flu 

The symptoms of flu will usually peak after two to three days and you should begin to feel much better within five to eight days. 

However, you may have a lingering cough and still feel very tired for a further two to three weeks.

Flu can give you any of these symptoms:

  • sudden fever – a temperature of 38°C (100.4°F) or above
  • dry, chesty cough
  • headache
  • tiredness
  • chills
  • aching muscles
  • limb or joint pain
  • diarrhoea or upset stomach
  • sore throat
  • runny or blocked nose
  • sneezing
  • loss of appetite
  • difficulty sleeping

When to visit your GP

If you are otherwise fit and healthy, there is usually no need to visit your GP if you have flu-like symptoms. 

The best remedy is to rest at home, keep warm and drink plenty of water to avoid dehydration.

You can take paracetamol or ibuprofen to lower a high temperature and relieve aches.

You should visit your GP if you have flu-like symptoms and you:

  • are 65 years of age or over
  • are pregnant
  • have a long-term medical condition, such as diabetes, heart disease, lung disease, kidney disease or a neurological disease
  • have a weakened immune system (the body's natural defence against infection and illness)

Flu can be more serious for these groups and antiviral medication may need to be prescribed.

Read more about how to treat flu and who should see a doctor.

Cold or flu?

Do you know the difference between a cold and flu? An expert explains the conditions, treatments and remedies available.

Media last reviewed: 11/07/2013

Next review due: 11/07/2015

Flu or cold?

The symptoms of flu and the common cold can be similar. Here's how to tell the difference:

Flu symptoms

  • come on quickly and include fever and aching muscles
  • make you feel too unwell to continue your usual activities

Cold symptoms

  • come on gradually
  • affect just your nose and throat
  • are fairly mild, so you can still get around and are usually well enough to go to work

Help fight flu

Sign up for the flu survey to help researchers at the London School of Hygiene and Tropical Medicine track the spread of flu and discover more about it. The survey takes just a few minutes each week and anyone can take part.

Page last reviewed: 16/05/2013

Next review due: 16/05/2015