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    Flu symptoms

    On this page
    1. What is flu?
    2. What are the symptoms of flu?
    3. How do symptoms of the flu differ from a cold?
    4. How can I treat flu symptoms?
    5. How can I prevent flu?

    What is flu?

    Flu (short for influenza) is an infectious illness caused by the influenza virus. It is especially common during the winter, although you can catch it all year round. It is spread mainly through coughs and sneezes, but you can also pick it up from simply being near someone who is infected or touching something they have been in contact with. This leads to a range of unpleasant flu symptoms.

    What are the symptoms of flu?

    People with flu will normally experience symptoms for 3-5 days but cough, tiredness and malaise may last for 1-2 weeks.

    The most common symptoms of flu are:

    • a sudden fever (above 38°C or 100.4°F)
    • headache
    • tiredness
    • dry cough
    • sore throat
    • chills
    • aching muscles
    • runny or stuffy nose

    Other possible symptoms include:

    • diarrhoea
    • vomiting/nausea
    • sneezing

    How do symptoms of the flu differ from a cold?

    Although they share some symptoms, flu and the common cold are actually different illnesses. They are caused by a different group of viruses, and flu can be much more severe than a cold.

    There are hundreds of viruses that cause colds, and only three strains that cause flu. However, these three strains are constantly evolving which is why the vaccine changes every year to protect against the most common ones. There is no vaccine against the common cold.

    Symptoms of a cold include:

    • runny or blocked nose
    • sore throat
    • cough
    • sneezing

    People suffering from a cold may also have a mild fever, tiredness and headache, which can make it easy to confuse with flu.

    The symptoms of a cold develop over one or two days, whereas flu comes on much quicker. You will usually recover from a cold within a few days, although some colds can last up to two weeks.

    How can I treat flu symptoms?

    Most people recover effectively from flu by resting at home, although you should see your GP if you:

    • have a very high fever together with abdominal or chest pain or an unusually severe headache
    • are aged 65 or over
    • are pregnant
    • have heart disease, diabetes, asthma, lung disease or another long-term medical condition
    • have a weakened immune system

    If you do not fall into any of these categories, your body should recover from flu on its own over a few days. To help your recovery you should get lots of rest and drink plenty of water to stay hydrated. You can treat the symptoms of flu by taking the following medications if you are safe to do so:

    • paracetamol to lower fever
    • ibuprofen for muscle aches
    • a decongestant to help with a blocked nose
    • cough syrup if you have a cough

    How can I prevent flu?

    Good hygiene

    Flu is spread by germs, so reducing your chances of picking up germs will lower the risk of you becoming infected. You should:

    • wash your hands regularly with water and soap
    • wash your hands or use hand sanitiser before eating anything with your hands
    • regularly clean surfaces such as door handles and computer keyboards to eliminate germs
    • cover your mouth with tissues when you sneeze or cough
    • avoid leaving tissues lying around - instead put them in the bin as soon as possible

    Antiviral medicines

    As well as speeding up the recovery process once you have flu, Relenza and Tamiflu can also prevent you from becoming infected in the first place. You may be considered for one of these if:

    • there is a flu virus going around
    • you have been in contact with someone in the same household or residential setting who been diagnosed with the flu in the last 48 hours
    • you have a medical condition which puts you at higher risk of flu, such as diabetes or heart, lung or kidney disease, and have not been adequately protected with the flu jab

    The flu jab

    You're eligible for a free NHS flu vaccine if you:

    • are 50 and over (including those who'll be 50 by 31 March 2022)
    • have certain health conditions
    • are pregnant
    • are in long-stay residential care
    • receive a carer's allowance, or are the main carer for an older or disabled person who may be at risk if you get sick
    • live with someone who is more likely to get infections (such as someone who has HIV, has had a transplant or is having certain treatments for cancer, lupus or rheumatoid arthritis)
    • frontline health or social care workers

    No vaccine is a 100% effective, but people who have had the flu jab are much less likely to get flu. You should speak to your GP in the autumn if you think you need a flu vaccination, to ensure you are protected over the winter period.


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