Cold, common

The common cold is a general term that is used to refer to a mild, self-limiting viral infection of the upper respiratory tract. Self-limiting means that a condition gets better by itself without the need for treatment.

The upper respiratory tract is made up of:

• the nose,
• throat,
• sinuses (the small spaces in the skull behind the eyes and nose),
• trachea, also known as the windpipe (the main airway that leads to the lungs),
• larynx (voice box,) and
• bronchial tubes (the airways in the lungs).

A cold can cause symptoms that include:

• nasal stuffiness,
• runny nose,
• sneezing,
• sore throat, and
• cough.

How common is the cold?

As the name suggests, a cold is thought to be one of the most common health conditions.

Adults experience an average of 2-4 colds a year and children experience an average of 3-8 colds a year. As a child’s immune system is underdeveloped compared with an adult’s, they are more vulnerable to infection.

Women get more colds than men, possibly because they are more likely to come into close contact with children.

The cold is not caused by a single virus - there are over 200 hundred different viruses that can cause cold symptoms. Due to the large number of viral infections that can potentially cause a cold, a cure or a vaccine for the cold is an unlikely prospect; at least in the short to medium term.

The cold is contagious

The viruses that are responsible for the cold are airborne, which means that they can survive for a short time in the outside environment. Therefore, a cold can be spread through:

• direct contact - for example, if you sneeze or cough, tiny droplets of fluid containing the cold virus are launched into the air and can be breathed by others, and
• indirect contact - for example, if you sneeze on a door handle and someone else touches the handle a few minutes later, they may catch the cold virus if they then touch their mouth or nose.

Colds are more common in the winter

The common cold is more frequent during the winter months. It used to be thought that this was because during the winter people are more likely to stay indoors and be in close contact with each other. However, this assumption is now not accepted by all experts.

As one researcher pointed out, people who use the London Underground on a regular basis spend a large part of their time in close contact with each other yet higher rates of colds have not been found in passengers on the Underground.

Also, research that was carried out in 2005 suggested that there may be some truth in the belief that cold weather could make people more vulnerable to developing a cold infection. However, further research is required in order to confirm this.

Outlook

The outlook for people with a cold is excellent and most cases will pass within seven days without the need for treatment.

Although there is no cure for a cold, it is possible to relieve the symptoms using self-care techniques, such as drinking plenty of fluids and taking over-the-counter (OTC) medication, such as paracetamol. See the treatment section for more information.