Medically reviewed by Jonathan B. Jassey, DO Coughing up thick, green mucus may indicate a bacterial or, less often, viral infection, but that's not always the case. You constantly breathe in bacteria ...

If you have had yellow or green snot for over 10 days, Dr. Connor suggests seeing a doctor who can prescribe antibiotics. Blood is present in large amounts.

Green mucus is a clue that your body is doing that job. “Mucus is really sticky,” Eddy said. “That’s good because when irritants like allergens, viruses or bacteria get into our nose, ...