A cold or the flu? Or COVID-19?

Maremare, rewharewha, mate korona?

Having a cold, the flu or COVID-19 is now common during the short, cold days of winter. It's good to know the difference.

Coldsinfluenza (the flu) and COVID-19 all affect your airways and how you breathe. This means they are easily confused with one another. While a cold is not usually serious, the flu and COVID-19 can be. 

Image credit: Canva

If you have symptoms, get a COVID test and if you are (or think you might be) positive, get somebody else to pick up cold and flu medicines for you, don't go into a pharmacy yourself. 

Could it be COVID-19?

Symptoms of COVID-19 are similar to having a cold or the flu.

Symptoms of COVID-19 can include:

  • a cough
  • a fever (temperature of 38˚C or higher)
  • shortness of breath
  • a sore throat
  • sneezing and runny nose
  • temporary loss of smell
  • upset stomach, possible with diarrhoea (runny poo) or vomiting (being sick).

If you have any of these symptoms, get tested for COVID-19.

What's the difference between a cold and the flu? 

A cold is a mild illness lasting 1 to 2 weeks, although some symptoms can last longer, eg, a cough.

  • Early symptoms can include a sore throat, sneezing, runny nose, mild fever.
  • After a few days, snot usually becomes thicker and may turn a greenish or yellowish colour.
  • It doesn't usually involve muscle pain.
  • It can include a mild headache (congested sinuses).It can include a cough.

Complications can include sinus congestion and ear infection.

The flu (influenza) is a moderate to severe illness with sudden onset of symptoms lasting 7 to 10 days.

  • There can be sudden onset of:
    • fever (temperature of 38°C or higher)
    • shivering
    • muscle aches
    • extreme tiredness
    • headache, sometimes severe
  • It can include a dry cough that can become moist
  • Bed rest is needed.
  • The cough and tiredness can last for weeks after the rest of the illness is over.

Possible complications are bronchitis and pneumonia.

(TriStar Health, USA, 2018)

Looking after yourself with a cold or the flu

  • Rest at home.
  • Drink plenty of fluids to stay hydrated.
  • If you have a sore throat, suck a teaspoon of honey or gargle with salt water. Adults can also try using a gargle, throat spray or pain-relief (anaesthetic) lozenges. Don't give honey to children under 12 months old.
  • For a blocked or runny nose ask your pharmacist about decongestants and saline nasal sprays.
  • For a cough sip a lemon and honey drink or ask your pharmacist about cough lozenges or medicines that may be suitable for you. Cough medicine doesn’t cure a cough but may give you some relief.
  • For aches and pains try paracetamol OR cold and flu medicines (check doses carefully and ask your doctor or pharmacist what is safe for you).

When to seek advice for colds or the flu

You can treat most colds and flu-like illnesses with rest and self-care at home, but you need to know when to seek medical help.

Phone your medical clinic for advice if you:

  • are not getting better
  • are pregnant
  • have diabetes or a health condition affecting your breathing, heart or immune system
  • are aged 65 or older
  • have a sore throat and are Māori or Pasifika aged 3–35 years
  • are concerned or not sure what to do.

If you are unsure what to do phone Healthline free on 0800 611 116 or your doctor for advice.

When to seek immediate medical help

If you have any of the following signs you may be seriously unwell and need emergency care: 

  • difficult or painful breathing
  • bluish lips or tongue
  • chest pain
  • coughing up blood
  • severe shaking, rigors
  • confusion or difficult to wake
  • stiff neck
  • rash with purple or red spots or bruises
  • clammy skin
  • not urinating or dark coloured pee
  • feeling faint or passing out (fainting).

Phone 111 or go to the hospital emergency department right now. Do not delay.

How to prevent flu and COVID

Vaccination is the best way to avoid getting COVID-19 and the flu. Read more about COVID vaccination and flu vaccination.

Other things you can do to stop the spread:

  • Wash your hands for 20 seconds and dry them well.
  • Cover your coughs and sneezes.
  • Avoid touching your face.
  • Don’t share toothbrushes, cups, food utensils or towels.
  • Clean and disinfect surfaces, like doorknobs, often.
  • Stay home if you're sick and avoid close contact with others.

Learn more about preventing the spread of COVID-19.

Learn more

Keep your immune system strong Health Navigator NZ
Health Navigator NZ
Influenza Health Navigator NZ
Influenza (flu) topics Health Navigator NZ

Reviewed by

Dr Sharon Leitch is a general practitioner and Senior Lecturer in the Department of General Practice and Rural Health at the University of Otago. Her area of research is patient safety in primary care and safe medicine use.
Credits: Health Navigator Editorial Team.