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Babylon Health

What is the flu?

The flu is a really common virus that can make you feel quite ill. It affects the lungs, nose and throat. Although the flu can be similar to the common cold, flu symptoms tend to be more severe. The flu also usually lasts longer than a cold. You can catch flu at any time but it's more likely during flu season in the fall and winter.

Like all viruses, the flu is contagious. That means it can spread from person to person through coughs and sneezes. A person with the flu can release up to 200 million viral particles when they sneeze or cough. These droplets can be breathed in by others and cause them to get sick too.

The flu virus can also survive on hard surfaces, such as counters and door handles. Someone can catch the flu by touching an infected surface and then touching their face. That’s why washing your hands regularly is a good way of preventing the flu.

Anyone can catch the flu but young children and elderly people are more likely to come down with the illness. Most people will make a full recovery from the flu, but sometimes it causes serious complications. Flu complications include pneumonia and chest infections. Sometimes people with the flu have to go to hospital.

Many people get a yearly flu vaccine to reduce the chances of them catching the illness. The CDC recommends everyone over six months get a flu jab. And it's particularly important to get one if you:

  • are 65 or older
  • have a weakened immune system
  • have diabetes, asthma or heart disease
  • live in a care home
  • are a healthcare worker

Symptoms of the flu

It can often be hard to tell the difference between the flu and a cold. But you'll usually feel far more unwell with flu and the symptoms will last longer. Flu symptoms often come on very quickly. And a high fever and chills is more common with the flu than the common cold. Vomiting and diarrhea are also more likely if it's the flu.

The main symptoms to look out for are:

  • Fever
  • Chills
  • Cough
  • Sore throat
  • Muscle aches
  • Headache
  • Tiredness
  • Vomiting
  • Diarrhea
  • Respiratory problems


You won't usually need to see a doctor if you have the flu unless you experience complications. Most of the time, the flu can be managed at home with lots of rest.

But if you're worried, feel very ill or have any of the following risk factors, book a medical appointment today:

  • Young child under 5 years of age
  • Aged 65 or over
  • You are pregnant
  • Have a long-term medical condition such as diabetes, asthma, or a heart disease
  • Have a weakened immune system – because of an illness or medication you’re taking

You should seek medical advice straight away if you experience any of the following symptoms:

  • Difficulty breathing or shortness of breath
  • Trouble swallowing food or drink
  • A persistently high fever
  • Feel confused or drowsy


Having the flu feels miserable but there are many ways to relieve the unpleasant symptoms. The main thing is to make sure you get plenty of rest and stay warm. Other things that might help are:

  • Antiviral medicines - they can sometimes shorten the illness by a day or two (these meds need to be started within 2-3 days of initial symptoms to be helpful)
  • Nasal strips and humidifiers
  • Drinking lots of fluids
  • Warm showers
  • Over-the-counter decongestants
  • Pain relievers like Tylenol
  • Cough syrup or cough drops


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When should I see my doctor when I have the flu?

People in high risk groups like pregnant women, the elderly, and children under six may need to see the doctor if they have flu. These people have a greater chance of developing complications from the flu such as pneumonia, bronchitis or having to go to hospital. If your symptoms don’t go away after two weeks, you should call your doctor.

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How can I tell if I have a cold or the flu?

The common cold and the flu have similar symptoms. But you will have more severe symptoms if you have the flu. High fever and chills tend to be more flu related. Special tests can be done within the first few days of the illness to let you know if you have the flu.

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Does the flu have any long-term effects?

You’ll be glad to hear that the flu doesn’t usually have any long-term effects. But if a secondary infection does occur, such as pneumonia, the recovery time will be longer than usual.

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What else can I do to protect myself from the flu?

Getting the flu shot annually is the best way to protect yourself from getting the flu. But you should also be sure to wash your hands regularly and avoid people who you know have the flu. Avoid touching your face and always stay home if you don’t feel well.

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Can I die from the flu?

Most people will make a full recovery from the flu. But in rare cases, it can be deadly especially in high-risk groups, like the elderly and very young children. Flu can lead to death if the virus triggers severe inflammation in the lungs. The flu can also cause your brain and heart to become inflamed, leading to serious complications. However, most healthy adults don’t have to worry about dying from the flu.

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What should I do if I have the flu?

Drink plenty of fluids, as this will help you to avoid dehydration. Get plenty of rest to boost your immune system in fighting off the virus. Take over-the-counter pain relievers to ease headaches, body aches and pains.

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Can your body fight the flu on its own?

Your body naturally has ways to fight off cold and flu viruses—and you can help fight it off faster with the right remedies. The flu is also an upper respiratory illness caused by one of several specific flu viruses. Because of this, the flu can lead to other respiratory problems if not taken care of. Call your doctor if your breathing becomes more difficult.

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Will you get the flu if you are exposed to it?

Although you were exposed to the flu, you do not worry about having the virus if you have no symptoms. Symptoms usually start within 1 to 4 days of close contact with another person. Seven days is an outer limit. If 7 days have passed, you should not worry about getting the flu from your recent exposure.

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What is the most common flu virus?

There are four types of flu virus: influenza A, B, C and D. Influenza A causes the majority of illnesses during flu season. It spreads fast due to its dynamic, faster changing nature and large host range. It’s the only type of flu that could cause a pandemic. Swine flu and bird flu are both types of influenza A. Influenza B is rarer than type A but it can also cause seasonal epidemics. Both influenza A and B are extremely contagious and cause the same type of illness and symptoms. Influenza C seems to cause mild illness while Influenza D does not seem to infect humans.

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How long is the flu contagious?

Most healthy adults may be able to infect others beginning on day 1. Those with the flu can even spread it before symptoms develop and up to 5 to 7 days after becoming sick. Children and some people with weakened immune systems may pass the virus on for longer than 7 days.

The information provided is for educational purposes only and is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Seek the advice of a doctor with any questions you may have regarding a medical condition. Never delay seeking or disregard professional medical advice because of something you have read here.