What the color of mucus – or snot – means is very misunderstood. The color of the mucus that comes out of your nose when you are sick, whether green, yellow or white, does not necessarily indicate a bacterial infection.
An upper respiratory infection typically starts out as a virus, which causes your body to produce excess mucus. When your body mounts an immune response to the virus, the white cells fighting the illness release an enzyme that changes the color of mucus.
Green snot is simply a sign your body is working hard to fight the infection. The best sign you have a bacterial infection and need to see a doctor is not the color of your mucus, but the duration or severity of your illness. If your symptoms have not improved or have even gotten worse after 7 to 10 days, it is time to make an appointment with your physician.
Unfortunately, excess mucus in your nose provides a nice, warm, wet place for opportunistic bacteria to set up camp. A bacterial infection may need an antibiotic intervention to get the message that they are not welcome.
Allen Marshall, MD, is an ear, nose and throat physician with Wake Specialty Physicians – ENT.