Flu FAQs

How long does flu last?

Primary symptoms of flu (fever, fatigue, body aches, chills, headaches, sore throat and cough) are usually at their worst for between 3 and 4 days.

A cough may linger a little longer, but full recovery can take between 7 and 10 days. Some people do experience a little fatigue for a few weeks once other symptoms clear up.

How long is flu contagious?

The flu virus is at its most contagious between 24 to 72 hours of becoming infected, but can be spread for up to 7 days once symptoms start. The virus can live in your mucus for 24 hours before you even begin to feel unwell.

It is best to stay home and rest at least 24 hours once your fever has broken without the use of fever-reducing medicines. Once your fever has gone for at least a day, you are no longer contagious. Young children can still spread the flu virus after 2 weeks of feeling unwell.

Can I exercise when I have the flu?

Regular exercise helps to strengthen your immune system and fight viral and bacterial infections. When you exercise, your white blood cells (the ones that help keep infections at bay) travel through your body faster and thus do their job a little quicker too.

But should you exercise when you’re feeling under the weather? When you have the flu what your body needs most is rest. Your immune system works best when it isn’t working overtime, and given that exercise temporarily suppresses the immune system, it’s best not to further weaken your body when you are ill.

Also, if you have a fever, you are likely at your most contagious, so it is better to skip the workout, especially if around other people. A high temperature pulls moisture out of your body. If you dehydrate or lose too much fluid, you could delay your recovery.

Wait it out (and rest) until at least 24 hours after your fever has broken (without the aid of medications) before you go back to your exercise routine.

What should you eat when you have the flu?

There’s an old saying, “Feed a cold, starve a fever.” Are there foods you should you be eating when you're down with the flu?

Like exercise, good nutrition is essential for your immune system, and is even more important when feeling under the weather. A well-nourished immune system helps fight a virus and what you eat will be key to how well you recover.

Foods that combat flu include:

  • Protein builds strength in the body, and is even more important when you are ill. Lean meat, poultry, fish, nuts and seeds, as well as legumes, dairy and eggs are good sources to tuck into.
  • Vitamins B6 and B12 help to keep your immune system in good working condition. Vitamin B6 comes in protein-rich foods such as potatoes, turkey, spinach and beans, as well as enriched cereal grains. Milk, meat and fish are good sources of vitamin B12, a powerful immune booster.
  • Vitamin C and folic acid can help to make you feel better faster. A good source is orange juice (especially when consumed with the pulp).
  • Minerals such as selenium and zinc are also good immune boosters. Also found in protein-rich foods such as nuts, beans, meat and poultry, these minerals will certainly help boost your immune system.
  • Flavonoids found in the soft white skin of citrus fruits (grapefruit, oranges, lemons and limes) can really boost your immune system, particularly when it’s at its lowest.
  • Antioxidants such as glutathione helps to strengthen the immune system and fight infections. Sources of this powerful antioxidant can be found in the red, pulpy area of a watermelon, in kale, broccoli, collard greens and cabbage.

Some people do find that dairy produces more mucus, as well as make any nausea or vomiting symptoms worse. You can avoid dairy altogether for a few days if you experience these symptoms and rather try and consume bland foods such as toast, rice, bananas and applesauce. You can also try sipping clear drinks to keep your fluid levels up. Chipped ice, juices, ginger ale and clear broths can help.

Warm decaffeinated tea with honey can help soothe a sore throat. If your airways are particularly congested, warm drinks are more beneficial for you than cold ones.

Warm decaffeinated tea with honey and lemon.

How effective is the flu vaccine?

The flu vaccine reduces the odds of contracting the flu virus by up to 60%. This figure does tend to vary from year to year and among different groups of people. The statistic generally applies to healthy people, and the effectiveness of a vaccine depends on a number of different factors:

  • Young woman receiving flu vaccine.Age: The vaccine is most effective in healthy adults. The vaccine is less effective in children under 24 months, who have weaker immune systems. The immune system also weakens naturally around middle age. People in this age group tend to find that the vaccine doesn’t work as well as it once did. It is important, however, for older people to get the vaccine as the virus can be more easily prone to possible complications in this age group.
  • General health: Vaccines work by spurring the immune system into action, “teaching” your body to identify a virus and “learn” how to defend against it. If you then become infected with the virus, the body can quickly recognise it and begin fighting it off. The effectiveness of the vaccine depends on how vigorously your body responds to it. A vaccine may not work as well with an immune system that is already weak or where there are chronic illnesses.
  • When you get the vaccine: It is best to get the flu vaccine before the flu season starts. The further you get into the flu season, the higher your risk of getting the flu. It takes about 2 weeks for the flu vaccine to take effect. If you are exposed to the flu virus in that period, you may still fall ill.
  • How well the current vaccine is matched with dominant flu strains: An annual flu vaccine is necessary for optimal protection as old vaccines aren’t always as effective year on year. Flu vaccines are often updated each season to protect you against dominant strains of flu for that year.

A flu vaccine unfortunately cannot guarantee that you won’t get flu, but it can help at least provide partial immunity. You may still fall ill, but your symptoms are likely to be somewhat milder.

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