Basics
A cold (flu-like infection) is an infection of the upper respiratory tract that is triggered by viruses. These viruses are particularly easy to transmit to other people. In many cases, secondary infections with bacteria occur. A cold should not be confused with the flu. The flu is also caused by viruses, but usually has a more severe course.
A cold, on the other hand, is usually quite harmless and passes after about a week. It occurs more frequently in the autumn and winter months. It can be assumed that everyone catches a cold about two to four times a year.