Green snot usually means a normal cold mid-fight - white blood cells cause the color, not bacteria. Worry instead about 10+ days without improvement, or getting better then worse.
What to do
Common questions
What does green snot mean?
Green snot is one of the most overread symptoms in medicine. The green comes from an enzyme released by your white blood cells as they fight off germs - it means your immune system is working, and it happens in completely ordinary viral colds. It does not, by itself, mean a bacterial infection, and it is a poor reason for antibiotics. This is why MedlinePlus and every major guideline steer treatment of most sinus symptoms toward rest, fluids, saline rinses, and time. The normal arc of a cold: clear runny nose for a few days, thicker yellow or green mucus in the middle, then clearing as you recover, all inside about 7 to 10 days. That pattern needs nothing but comfort care. What changes the answer: symptoms lasting past 10 days without improving, a pattern where you started to get better and then got worse - the double worsening that suggests a bacterial sinus infection on the heels of a virus - high fever with thick discharge and facial pain, or one-sided symptoms with swelling around the eye. Those earn a clinician visit. Recurrent sinus trouble is worth raising too, since allergies often sit underneath. Pymander is a free AI doctor, 24/7 by text. Describe your timeline and it can help you tell a normal cold arc from the double-worsening pattern.