Symptoms and causes of a common cold

by | Colds and Flu, Ear Nose and Throat Health, Respiratory Health

The common cold is an infection, mainly of the nose and throat, which is caused by a virus. It usually lasts about a week and should not cause serious illness in otherwise healthy people.

How do you get a cold?

A number of different viruses cause the common cold, but the rhinovirus is the most common cause. The virus, which is very infectious, can be spread from person to person by the fine spray shot from the nose and mouth when you cough or sneeze. It can also be spread by close contact (e.g. shaking hands) with someone who has a cold.

The virus can survive on indoor surfaces (such as door handles, light switches and taps) for days and can infect someone when they rub their eyes or nose after touching a contaminated surface.


Cold symptoms usually appear 1-3 days after exposure to the virus and include:

  • nasal congestion (blocked nose);
  • nasal discharge (runny nose);
  • sneezing;
  • sore throat;
  • coughing;
  • mild fever;
  • headache; and
  • red, watery eyes.

Relief for cold symptoms

There is no cure for the common cold, but treatments can relieve some of the unpleasant symptoms.

Antibiotics do not work against viruses and there are currently no antivirals available to treat colds. Antibiotics may occasionally be used to treat some bacterial infections that develop following a cold.

The following tips may help you to relieve some common cold symptoms.

  • Drink plenty of fluids. This replenishes the moisture lost during mucus production and makes mucus looser and easier to expel. Warm soup or warm water with lemon may also help soothe a sore throat and relieve congestion.
  • Adults and children older than 12 months of age can try honey to relieve a cough, especially at night time.
  • Rest is recommended to help your body fight off the cold. Staying at home will also limit the spread of your cold to other people.
  • Saline (salt water) nasal sprays or washes can help unblock the nose and clear the back of the throat. Nasal drops may be needed if a baby has a blocked nose and can’t suck or feed. Your doctor or pharmacist will tell you what’s best and how to use it.
  • Salt water gargle. Dissolve some salt in a glass of water and gargle to relieve a sore throat.
  • Sucking on ice can help relieve the pain of a sore throat. Adults and children older than 6 years may also want to try sore throat lozenges or sprays.
  • Vapour rubs may help a blocked or runny nose.
  • Antihistamines may improve runny noses and sneezing.
  • Decongestants, available as tablets and nasal sprays, may be helpful for some adults. Decongestants can provide short-term relief of congestion (blocked nose), but don’t use decongestants for more than a few days, otherwise you may suffer from rebound congestion (return of the symptoms). Children younger than 6 years should not use decongestants at any time, and those aged under 12 should take these medicines only if advised by a doctor or pharmacist. Decongestants should not be used if you have certain conditions (such as heart problems) – again, check with your doctor or pharmacist.
  • Painkillers, including paracetamol and NSAIDs (non-steroidal anti-inflammatory drugs) such as ibuprofen, can relieve aches and pains and reduce fever. Aspirin should not be given to children or teenagers. Paracetamol is included in many cold and flu preparations, so be careful to read labels and keep track of how much paracetamol you are taking.
  • Cough suppressants are not usually recommended, as coughing is the body’s way of getting rid of mucus. Some mixtures may help in the short term if your cough is dry and annoying, but they are not recommended at all for young children. Follow directions carefully.
  • Use soft tissues for blowing the nose as the area around the nose tends to become sore and irritated. Barrier cream may help protect the skin around the nose.
  • Vitamin C may help reduce the duration of a cold when taken before symptoms start. So taking vitamin C might be a good idea if you are frequently exposed to cold germs.
  • Zinc lozenges, when taken at the onset of cold symptoms, may reduce the length and severity of colds. Zinc can be associated with potentially harmful side effects, so check with your doctor before taking it.
  • Echinacea is of unknown effectiveness. Further studies are needed to work out if it helps relieve or prevent colds.

Always take medicines as directed by your doctor or pharmacist. Cold remedies should only be taken while you are feeling unwell – you should stop taking the medicine once you are better.

It’s very important that you know what ingredients are in a cold remedy because of the dangers of doubling up on treatment. For example, many cold and flu preparations contain paracetamol, so if you take more than one product with paracetamol in it, an overdose may occur.

Remember that all medicines, including complementary medicines and vitamin supplements, can cause side effects.

When to see a doctor

Go to your doctor if you or your child has any of the following:

  • the discharge is from only one nostril;
  • the nasal discharge is smelly;
  • fever higher than 38.5 degrees Celsius or chills;
  • earache or facial or sinus pain;
  • glands (lymph nodes) are significantly swollen;
  • the cold has lasted more than one week and symptoms are not improving;
  • persistent cough;
  • aching muscles;
  • neck stiffness;
  • severe headache;
  • sensitivity to light;
  • chest pain;
  • shortness of breath or difficulty breathing;
  • a skin rash or pale or mottled skin;
  • vomiting; or
  • unusual drowsiness.

In addition, take your baby or child to the doctor if they have:

  • a bulging fontanelle (the soft spot on top of the baby’s head);
  • excessive irritability;
  • high pitched cry;
  • loss of appetite; or
  • earache.

Stop the spread of germs

Take some time off and stay at home to rest when you have a cold. It will help you feel better and help stop the cold virus infecting others.

When you are around others, sneeze and cough into a tissue. If you don’t have a tissue, cover your mouth with your upper sleeve or inner part of your elbow rather than your hands. This can help stop the spread of germs from your hands to doorknobs and other surfaces.

Remember to throw any used tissues straight into the bin and to wash your hands frequently when you have a cold.