Common cold

Over 200 viruses can cause the common cold

What are colds?

A cold is a contagious viral disease which infects the upper respiratory tract. There are more than two hundred viruses that can cause the common cold which is why people can catch colds again and again. Most people will catch a cold two to four times a year - and they are much more common during the winter months. 

Common cold symptoms

The cold virus tends to attach itself to the soft, warm surfaces of the nose, throat and sinuses and hence, this is where the symptoms of the cold normally occur. The first symptom is often an irritation or soreness in the throat. However a large range of cold symptoms may be experienced.

The main symptoms of a cold in adults and older children are:

• a blocked nose
• cough
• headache
• sneezing
• runny nose
• feeling lethargic
• earache
• muscle pain
• sinus pain

Younger children and infants may experience other cold symptoms such as:

• problems feeding
• fever
• swollen glands
• being restless or uncomfortable

In most cases, symptoms of a common cold appear within one or two days of being infected by the virus and last for about a week.

What causes a cold

The majority of colds are caused by rhinoviruses which are found in invisible droplets of air that are breathed in or land on objects that are touched or picked up. There are more than one hundred different rhinoviruses that can make their way into the lining of the throat or nose. They trigger an immune system reaction which causes the symptoms of sore throat, headache and other common cold symptoms.

Although rhinoviruses are the main cause of colds, other viruses such as coronaviruses, adenoviruses and respiratory syncytial viruses are also common causes. It is due to the vast numbers of different viruses that can infect individuals that colds can be recurrent as, once you develop immunity to one virus, another virus may come along and cause a slightly different infection.

How do you catch a cold?

Colds are at their most contagious during the first two to four days after the symptoms appear in someone affected, and he or she can stay contagious for up to three weeks.

Colds are spread by virus particles in the air which are disseminated by sneezing or coughing. However you may also catch a cold through close personal contact with someone or even through indirect contact with an infected person.

For example if a person with the common cold touches their nose or mouth, thousands of virus particles are transferred onto their skin. When they then touch an object such as a door handle or chair, they leave virus particles behind. The next person to touch the object will pick up the virus and become infected.

Complications of the common cold

In the majority of cases, colds do not cause any major health problems. Although symptoms such as coughs or sore throats may be irritating and uncomfortable, with the common cold, symptoms do not tend to persist for more than one week. However, on rare occasions a cold can lead to complications.

In older children and adults colds may cause:

• inflammation of the sinuses
• a chest infection or pneumonia
• worsening of asthma

In younger children, middle ear infections are the most common complication of a cold and in the case of infants, a chest infection, pneumonia or croup may develop.

Common cold remedies

There are many different remedies for colds on the market - however there is no cure for the common cold.

• Antibiotics, which treat infections caused by bacteria, do not have any affect on cold viruses.
• If the cold is causing symptoms such as muscle pain, headaches or a sore throat, you can take pain killers such as ibuprofen or paracetamol to lesson any discomfort.
• Nasal sprays can help to clear a blocked nose
• Cough medicines or syrups may reduce any coughing fits.
• There are also a number of vitamin supplements which are popular in treating colds.
• Lastly, one of the most popular herbs to use is Echinacea, which helps the body fight the symptoms of the colds by strengthening the immune system.