A common cold is a viral infection of the nose and throat, affecting the upper respiratory tract. It is characterized by symptoms such as a runny nose, sore throat, and sneezing. More than 200 different viruses can cause a cold, with rhinoviruses being the most frequent culprits. Colds are highly contagious and spread easily from person to person.
How Cold Viruses Travel
Cold viruses primarily travel through tiny droplets released into the air when an infected person coughs, sneezes, or talks. These airborne droplets can then be inhaled by someone nearby, leading to infection. Another common transmission method is direct contact, such as shaking hands with an infected individual who has virus particles on their hands. If you then touch your eyes, nose, or mouth, the virus can enter your body through these mucous membranes.
Indirect contact also plays a significant role in spreading cold viruses. Viruses can survive on surfaces like doorknobs, keyboards, or toys for several hours. Touching a contaminated surface and then touching your face (eyes, nose, or mouth) can transfer the virus to your mucous membranes, causing infection.
When You’re Most Contagious
People infected with a cold virus are most contagious during the first few days of their illness. This period often includes the time before symptoms fully develop or when they are at their peak severity. The incubation period, which is the time between exposure to the virus and the onset of symptoms, ranges from 12 hours to three days. During this early stage, an individual can already transmit the virus to others without realizing they are sick.
Contagiousness is highest within the first one to four days after symptoms appear. Although symptoms like a cough or runny nose might linger for up to two weeks, the risk of transmission decreases significantly after about seven days.
Stopping the Spread of Colds
Practicing good hygiene is an effective way to prevent catching a cold or spreading one to others. Frequent handwashing with soap and water is important, especially after coughing, sneezing, or being in contact with someone who is sick. If soap and water are not available, an alcohol-based hand sanitizer with at least 60% alcohol can be used.
Avoiding touching your face, particularly your eyes, nose, and mouth, helps prevent the virus from entering your body. Cold viruses can easily transfer from your hands to these entry points. When coughing or sneezing, cover your mouth and nose with a tissue and then dispose of it immediately. If a tissue is not available, cough or sneeze into your elbow or upper sleeve instead of your hands. Staying home when sick is an important measure to avoid spreading the virus to others in workplaces, schools, or public spaces.