A cold is a mild viral infection of the nose, throat, sinuses and upper airways. It can cause a blocked nose followed by a runny nose, sneezing, a sore throat and a cough.
In adults and older children, the cold will usually last for about a week as the body fights off the infection. Colds in younger children can last up to two weeks.
There is no cure for a cold, although you can usually relieve the symptoms of a cold at home by taking over-the-counter medication, such as paracetamol, and drinking plenty of fluids.
Symptoms of a common cold
The first symptom of a cold is usually a sore or irritated throat.
This is then followed by other symptoms, including:
a blocked nose (nasal congestion) – caused by a build up of phlegm or mucus (catarrh)
nasal pain and irritation
a runny nose (nasal discharge) – the discharge is usually clear and runny at first before becoming thicker and darker over the course of the infection
coughing – this symptom occurs in one out of every three cases
a hoarse voice
a general sense of feeling unwell
Less common symptoms of a cold include:
a usually mild temperature (fever) of around 38–39°C (100.4–102.2°F)
earache – severe earache may be a sign of a middle ear infection (otitis media)
loss of taste and smell
mild irritation of your eyes
a feeling of pressure in your ears and face
The symptoms of a cold are usually at their worst during the first two to three days of the infection before they gradually start to improve. In adults and older children, the cold usually lasts for about a week. However, if you or your child has a cough, it may last for up to three weeks.
Colds tend to last longer in younger children who are under five. Their symptoms typically last from 10–14 days.
When to see a GP
You only really need to see your GP if:
your symptoms persist for more than three weeks
you have a high temperature (fever) of 39°C (102.2°F) or above
you cough up blood-stained phlegm (thick mucus)
you feel chest pain
you have breathing difficulties
you experience severe swelling of your lymph nodes (glands) in your neck and/or armpits
See your GP if you’re concerned about your baby, an elderly person, or if you have a long-term illness, such as a chest condition.
Tests may be needed to rule out a more serious infection such as pneumonia (a bacterial infection of the lungs) or glandular fever (a viral infection caused by the Epstein-Barr virus).
What causes a cold?
Colds are caused by viruses which attack the lining of the nose and throat, inflaming these areas. As they become inflamed, they begin to produce more mucus, resulting in a runny nose and sneezing.
More than 200 types of virus can cause a cold. Those most responsible for colds belong to one of two groups, rhinoviruses and coronaviruses.
Because a number of viruses can cause a cold, it’s possible to have several colds, one after the other, as each one is caused by a different virus.
How does a cold spread?
A cold can be spread through:
direct contact – if you sneeze or cough, tiny droplets of fluid containing the cold virus are launched into the air and can be breathed in by others
indirect contact – if you sneeze onto 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
In general, a person first becomes contagious two to three days before their symptoms begin, and they remain contagious until all their symptoms have gone. So most people will be contagious for around two weeks.
How can I prevent a cold spreading?
You can take steps to help prevent the spread of a cold. For example:
wash your hands regularly and properly, particularly after touching your nose or mouth and before handling food
always sneeze and cough into tissues as this will help to prevent the virus-containing droplets from your nose and mouth entering the air where they can infect others; throw away used tissues immediately and wash your hands
clean surfaces regularly to keep them free of germs
use your own cup, plates, cutlery and kitchen utensils
use disposable paper towels to dry your hands and face, rather than shared towels. As with tissues, always dispose of the paper towels after you have finished using them