Being contagious means that you are capable of transmitting an illness to another person through bodily contact or airborne droplets. The infection causing the illness may be viral or bacterial. Once you fall sick, it is important to determine whether you are contagious or not, as this may prevent you from contaminating other people. If you discover that you are contagious, precautionary measures should be taken to prevent the spread of the illness. This wikiHow article will help you to identify some of the most common symptoms of contagious illnesses and provide some helpful information on what to do next. Just see step 1 below to get started.