The common cold is a contagious disease. Viruses spread through the air and through direct contact. Cold viruses originate  inside the nose.  Sneezing and coughing spreads the virus through the air, just as direct contact of the hands, eyes and face causes contagion.

In order to avoid spreading a cold virus, some simple rules should be followed:

• Wash your hands frequently.

• Avoid contact with people who have a cold.

• maintain an adequate temperature and humidity in rooms. Viruses spread more easily in low humidity, while dry air weakens the respiratory tract.

Many people believe that vitamin C helps prevent colds but its effective use in prevention has not been conclusively proven. It may, however, be of help in alleviating cold symptoms.