What is the common cold?

The common cold is a viral infection that affects the upper respiratory tract. Colds can occur anytime, but are more common during the winter months. They can cause a sore throat, a stuffy or runny nose, coughing and sneezing. They are different to influenza, or ' the flu'. They are usually not very serious and generally get better by themselves within a couple of days to a week.

Upper respiratory tract

The nose, sinuses, larynx and trachea parts of the respiratory tract which function to carry air to and from the lungs.

Causes

A cold is caused by viruses that infect a person's upper respiratory tract, which includes the nose, sinuses, throat (pharynx) and voice box (larynx). There are more than 200 different viruses that can cause a cold, with rhinoviruses the most common cause. The viruses that cause colds are contagious, meaning that they can be easily passed on to another person. Colds can be spread by contact with an infected person, or by breathing in droplets from their sneeze or cough.

Viruses that cause a cold can enter the body through the nose or mouth, where they can affect different parts of the upper respiratory tract. Your body's immune system reacts to the infection to try to clear the virus. This can cause inflammation and excess mucus production, which cause the symptoms of a cold.

Immune system

The organs and cells involved in protecting the body against infection.

Mucus

A thick, viscous liquid that is secreted for lubrication and to form a protective lining over certain tissues.

Upper respiratory tract

The nose, sinuses, larynx and trachea parts of the respiratory tract which function to carry air to and from the lungs.

Signs and symptoms

The main symptoms of a cold include:

  • A stuffy or runny nose;
  • Sore throat;
  • Cough;
  • Headache, and;
  • Sneezing.

These symptoms can last from a couple of days to around a week. A cold can sometimes be confused with the flu, because they can cause similar symptoms, such as a sore throat and cough. But the flu, which is caused by the influenza virus, usually causes other more severe symptoms.

A cold can cause a runny nose and sneezing. 

Types of treatment

There is no cure for a cold, but getting lots of rest and drinking plenty of fluids may help your recovery. There are also some over-the-counter medications that can help to relieve some of the symptoms.

Medication

Pain-relief medications such as paracetamol, aspirin, or ibuprofen can help to relieve a sore throat, headache or earache. Decongestants, such as pseudoephedrine or phenylephrine, may help to relieve a blocked or stuffy nose. These can be taken as either a nasal spray or as a tablet.

Antibiotics do not help relieve a cold - these medications only help clear infections that are caused by bacteria.

Decongestant nasal sprays may help to relieve a blocked nose. 

Potential complications

Colds are not usually very serious and generally get better by themselves within a couple of days to a week. However, a common cold can sometimes lead to other complications including:

Prevention

There is no exact way to prevent getting a cold, but there are several things you can do to reduce your chance of developing one, or passing one on to others. These include:

  • Washing your hands often, especially after coughing or sneezing;
  • Avoiding close contact with people who have a cold;
  • Throwing tissues in the bin after using them, and;
  • Staying home from work or school if you have a cold.