A cold is a mild viral infection of the nose, throat, sinuses and upper airways. It's very common and usually clears up on its own within a week or two.
The main symptoms of a cold include:
• a sore throat
• a blocked or runny nose
• sneezing
• a cough
More severe symptoms, including a high temperature (fever), headache and aching muscles can also occur, although these tend to be associated more with flu.
 

In general, a person becomes contagious from a few days before their symptoms begin until all of their symptoms have gone. This means most people will be infectious for around two weeks.
You can catch the virus from an infectious person by:
• Touching an object or surface contaminated by infected droplets and then touching your mouth, nose or eyes
• Touching the skin of someone who has the infected droplets on their skin and then touching your mouth, nose or eyes
• Inhaling tiny droplets of fluid that contain the cold virus – these are launched into the air when an infected person coughs or sneezes
Colds spread most easily among groups of people in constant close contact, such as families and children in school or day care facilities. They're also more frequent during the winter, although it's not clear exactly why.
A number of different viruses can cause a cold, so it's possible to have several colds one after the other, as each one may be caused by a different virus.

cold symptoms usually  clear within a week or two.
seek medical advice if :

•  Your symptoms persist for more than three weeks
•  Your symptoms get suddenly worse
•  You have breathing difficulties
•  You develop complications of a cold, such as chest pain or coughing up bloodstained
• mucus
• or develop high grade fever

•  Resting, drinking plenty of fluids and eating healthily
•  taking over-the-counter painkillers, to reduce any fever or discomfort
•  Using decongestant sprays or tablets to relieve a blocked nose
•  Trying remedies such as gargling salt water and sucking on menthol sweets

Many painkillers and decongestants are available from pharmacies without a prescription. They're generally safe for older children and adults to take, but might not be suitable for babies, young children, pregnant women, people with certain underlying health conditions, and those taking certain other medications. Speak to your doctor if you're unsure.

. You can take some simple steps to help prevent the spread of a cold. For example:
• Wash your hands regularly, particularly before touching your nose or mouth and before handling food
• Always sneeze and cough into paper tissues – this will help prevent the virus-containing droplets from your nose and mouth entering the air, where they can infect others; you should 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
• Don't share towels or toys with someone who has a cold