Te rewharewha Flu (influenza)

The flu (influenza) is a virus that spreads quickly between people. Flu causes symptoms like a fever, runny nose, cough or upset stomach. There can be different types or strains of flu that can make you sick each year.

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How flu spreads

Flu (influenza) spreads quickly from person to person through touch and through droplets in the air. This includes:

  • direct contact with people who have flu
  • contact with surfaces that have the flu virus on them
  • coughing
  • sneezing
  • talking.

You are most likely to get the flu during 'flu season' — May to October in Aotearoa New Zealand.

Adults are most likely to be contagious in the first 3 to 5 days of illness. Young tamariki can be contagious for more than 5 days.

Symptoms of flu

The flu virus infects your nose, throat and lungs. It is normally worse than a cold.

It can take between 1 to 4 days to feel symptoms after you catch flu. The worst symptoms usually last about 5 days, but coughing can last up to 2 to 3 weeks.

Symptoms of flu start suddenly and can include:

  • fever or feeling feverish
  • chills
  • muscle or body aches
  • headache
  • runny or stuffy nose
  • cough
  • sore throat
  • upset stomach, vomiting or runny poos (diarrhoea).

Illnesses with similar symptoms

Flu symptoms can be similar to other illnesses like COVID-19 or meningococcal disease. If you suspect someone in your whānau has meningococcal disease, seek urgent medical attention.

Complications of flu

Some people get very sick with flu. It can cause serious complications, like chest or sinus infections.

In severe cases people need to stay in hospital. Around 500 people die from the flu each year.

People at higher risk of getting complications from flu include:

  • pregnant people and those who have just given birth
  • people with an ongoing health condition — like asthma, diabetes, cancer, a heart or lung condition, and conditions that affect the nervous or immune systems
  • significantly overweight people
  • Māori and Pacific peoples aged 55 and over
  • people aged 65 years or over
  • pēpi and tamariki, especially under 5 years
  • people with serious mental health or addiction issues.

When to get immediate medical advice

Get urgent medical advice if you or a whānau member have:

  • a high fever that does not come down, especially if you are pregnant
  • chills or severe shaking
  • a rash
  • difficulty breathing or chest pain
  • purple or bluish colour of your lips, skin, fingers or toes
  • severe headache or stiff neck
  • dislike of bright lights
  • fits (seizures or convulsions)
  • signs of dehydration such as dizziness when standing
  • difficulty passing urine regularly.

If a person you take care of is less responsive than normal, unusually quiet, or confused, call your healthcare provider urgently.

Let your healthcare provider know if you or a whānau member were starting to feel better, then get worse.

Flu danger signs in pēpi and tamariki

You should get medical help if your pēpi or tamariki:

  • has a fever and is under 3 months old
  • will not take feed or take fluids — do not force them
  • has fast or noisy breathing or if they are wheezing or grunting
  • has the area below the ribs sucking inward instead of expanding when they breathe in
  • is very pale
  • is drowsy or difficult to wake
  • is irritable, for example not wanting to be held
  • is limp or unable to move
  • has dry nappies or no tears when they are crying — this means they are dehydrated
  • has signs of other serious conditions, such as meningitis
  • has a rash.

Diagnosing flu

Healthcare providers do not usually test for flu. They usually diagnose you based on your symptoms.

Your healthcare provider may do a physical exam and look for signs and symptoms of flu. They might order tests to make sure it is not a different illness if you have serious symptoms.

If you do catch flu, it is important that you stay away from work or school while you are unwell.

Treating flu

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If you are unwell, stay at home and rest in a separate, well-ventilated room away from other people if you can.

Drink small amounts of fluids often.

You can also take appropriate medicines to relieve discomfort and fever if you need to.

When pēpi or tamariki have flu, it is important to do the following.

  • Keep them at home resting until they are well.
  • Care for them in a separate, well-ventilated room away from others if possible.
  • Breastfeed more or give them more of the fluids they usually drink.
  • Give paracetamol or ibuprofen if they have pain or discomfort in the dose recommended on the package, unless your healthcare provider says otherwise. Do not give aspirin to tamariki under 14 years of age.

Preventing flu

The flu virus changes often. This means the vaccine has to be adjusted each year to match the new strains of the disease. Your best defence against flu is to get a yearly flu vaccine and follow basic hygiene practices.

Some people can get flu vaccines for free. Find out about flu vaccines and when to get them.

Flu (influenza) vaccine (internal link)

Other ways to avoid flu

You can also protect yourself and your whānau in other ways. 

  • Wash your hands regularly for at least 20 seconds, and dry them for 20 seconds — or use an alcohol-based hand rub. 
  • Do not share drinks.
  • Avoid crowded places.
  • Cover your mouth and nose when you cough or sneeze.