Flu, also known as influenza, is a respiratory illness caused by a virus, usually influenza A or B. The flu viruses constantly change so this winter’s flu strains will be slightly different from previous years. Flu can affect anyone but if people have a long-term health condition, the effects of flu can make it worse even if the health condition is well managed and they normally feel well.
Flu symptoms come on very quickly and can include:
- a sudden high temperature
- an aching body
- feeling tired or exhausted
- a dry cough
- a sore throat
- a headache
- difficulty sleeping
- loss of appetite
- diarrhoea or tummy pain
- feeling sick and being sick
The symptoms are similar for children, but they can also get pain in their ear and appear less active. They may also present differently with flu – for example, without fever but with diarrhoea.
People with the flu can be infectious 1 day before to 3 to 5 days after symptoms appear and the virus is spread by breathing in droplets coughed out into the air by infected people or by the droplets landing on mucous membranes. Transmission may also occur by direct or indirect contact with respiratory secretions for example via soiled tissues or from contaminated surfaces. Flu spreads easily in crowded populations and in enclosed spaces.
To reduce the risk of spreading flu
- wash your hands often with warm water and soap
- cover your mouth and nose with a tissue when you cough or sneeze
- bin used tissues as quickly as possible
- get the flu vaccine
What you need to do
Anyone unwell and with a high temperature should stay at home and avoid contact with other people until their temperature is normal and they are well enough to return to work or school
The risk of infection can be minimised through the flu vaccination. The vaccine is safe and effective and is offered every year through the NHS to help protect people at risk of getting seriously ill from flu.
For more information on the flu vaccine, please visit the Flu vaccines page.