A lot of people think yellow or green snot means you need an antibiotic. That is not true. Laura Martin, MD, MPH If it's a viral infection causing the yellow or green snot, yellow in particular is ...

If you are in a heavily polluted environment, your snot may look green. If you have hay fever, it may be clear. In fact, a common cold may also cause your snot to look yellow or green. If your ...

Coughing up thick, green mucus may mean a bacterial or, less often, viral infection, but that's not always true. You ...