What is a cold?

A cold is a viral infection that usually affects your upper respiratory tract, including your nose and throat.

Colds are very common. Adults on average can get 2 to 4 colds each year. Children often get many more colds, up to 8 colds per year.

Colds are more common in winter.

A cold is not the same as the flu (influenza). The flu is caused by a different virus and usually makes you feel much more unwell. It can sometimes be hard to tell the difference between a cold and the flu at first, because some early symptoms can feel similar. The flu can be serious and may lead to complications, especially in babies, older people, pregnant females and people with long-term health conditions.

What are the symptoms of a cold?

If you have a cold, you may develop some of these symptoms:

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

Sometimes you can also have a low-grade fever. Fever with a cold is more common in children than in adults.

Your symptoms will usually be mild. They peak on day 3 or 4. Most of the time you will feel better within 7 to 10 days.

Sometimes your cough may linger even after your other symptoms have gone away.

Read more about respiratory viruses.

What causes a cold?

There are more than 200 types of viruses that can cause a cold. Most cold viruses belong to 1 of 2 groups:

• rhinoviruses
• coronaviruses

The viruses that cause a cold are highly contagious (infectious). Colds may be spread by:

• touching people, surfaces or objects that have the cold virus on them
• breathing in the virus from the air and when infected people cough or sneeze

If your child has an infectious condition, you may need to keep them home from day care or school to stop it from spreading. Read the list of common childhood illnesses, including colds and flu, and their recommended exclusion periods.

When should I see my doctor?

You should visit your doctor if:

• you are feeling unwell and you are worried about your health
• you are worried you are dehydrated
• your symptoms, including your cough, persist — you may be referred to a specialist for some tests.

When should I call an ambulance or visit an urgent care clinic?

If you need to see your doctor but cannot wait for an appointment, you may be able to get treatment at a Medicare Urgent Care Clinic. Use the Service Finder to find your nearest one.

You should call for an ambulance or go to an emergency department if you are having trouble breathing.

You should also call an ambulance or go to an emergency department if your child has a cold and:

• has a fever and is less than 3 months old
• is having trouble breathing
• can't stop vomiting, isn't drinking or feeding
• is difficult to wake up — they seem floppy, sleepy and are less responsive than usual
• cannot be comforted
• is not passing urine (wee) — has not had a wet nappy for a few hours
• their skin has a rash that does not fade when you press on it or is blue or grey

If your child has any of these symptoms, or if you feel worried, you should call an ambulance or go to an emergency department. See Fever in children and Symptoms of serious illness in babies and children for more information.

How is a cold diagnosed?

Your doctor can diagnose your cold by asking you about your symptoms and examining you. Your doctor may:

• check your temperature
• look at your throat and ears
• listen to your chest with a stethoscope

Sometimes your doctor will recommend some tests to find out which virus is causing your symptoms or to check for complications.

If you are generally healthy, you will probably not need to see a doctor to be diagnosed.

You can also test yourself for some viruses that cause cold and flu symptoms with a rapid antigen self-test (RAT). You can buy these from chemists and supermarkets.

How is a cold treated?

Treatment for your cold focuses on relieving your symptoms. There is no cure for a cold.

In most cases, you can treat your symptoms yourself with over-the-counter (OTC) medicines. Most people will get better by themselves within 7 to 10 days without any treatment.

Read about the difference between bacterial and viral infections.

Self-care for colds

Some things you can do to relieve cold symptoms include:

• getting plenty of rest
• drinking plenty of fluids (liquids)
• using saline nasal drops or nose sprays

Cold medicines

OTC medicines to help relieve your symptoms include:

• pain relief medicines — paracetamol and non-steroidal anti-inflammatory drugs (NSAIDs)
• throat lozenges or sprays
• decongestants — nose sprays or pills to help relieve your blocked nose
• antihistamines combined with oral decongestants or pain medicines
• cold and flu tablets — a combination medicine that has a few types of medicines in one pill

Take extra care when taking cold and flu tablets, as these often contain paracetamol. Ask your pharmacist which medicines can be taken together.

Your doctor can also prescribe an inhaled medicine called ipratropium.

Do not give aspirin to children.

Do not give OTC cold medicines to children younger than 4 years.

Ask your doctor or pharmacist about other medicines for colds and flu.

Always ask your pharmacist and check the instructions on cold medicines before using them. You may ask your doctor to prescribe antibiotics. Remember, antibiotics do not help you recover from a cold. This is because they only treat illnesses caused by bacteria while colds are caused by viruses.

What are the complications of a cold?

Complications of colds are usually rare and can include:

• ear infections
• sinusitis
• pneumonia
• secondary bacterial infections

Colds can also make other conditions worse, including asthma and chronic obstructive pulmonary disease (COPD).

Can a cold be prevented?

Good hygiene is one of the most important ways to help prevent catching or spreading a cold. Below are some tips to ensure good hygiene:

• Wash your hands regularly. Hand sanitiser can be used when soap and water are not available, particularly after touching your nose or mouth, after using the toilet and before touching food.
• Sneeze and cough into your elbow or a tissue (then throw the tissue away immediately and wash your hands).
• Clean surfaces such as your computer keyboard, telephone and door handles regularly to get rid of germs.
• Do not share cups, plates and cutlery.
• Throw tissues in the bin immediately after using them.

Keeping a physical distance from other people when you have a cold also helps prevent spreading it to others. You should stay home when you are sick to stop the spread of colds.

There is no good evidence to show that vitamins and other supplements can prevent colds.

Resources and support

• Learn more about colds and flu with Queensland Health's factsheet.
• Read more about the difference between a cold and the flu and how colds are spread on the NPS Medicinewise factsheet.
• NSW Health has a collection of factsheets about different respiratory viruses you can catch.
• You can also call the healthdirect helpline on 1800 022 222 (known as NURSE-ON-CALL in Victoria). A registered nurse is available to speak with you 24 hours a day, 7 days a week.

Languages other than English

• The Royal Children's Hospital has translated their factsheet about viral illnesses into many community languages.
• The NSW Multicultural Health Communication Service has information on hand hygiene in community languages.

Information for Aboriginal and/or Torres Strait Islander peoples

• The Lung Foundation Australia has some resources for Aboriginal and/or Torres Strait Islander peoples about protecting yourselves against respiratory illnesses such as the flu, pneumonia and respiratory syncytial virus (RSV).
• Watch the Menzies School of Health Research's No Germs on Me video.