Is yellow mucus normal?

Yes — yellow mucus can be normal, especially when you have a cold or other upper respiratory infection. It usually means your body is responding to inflammation or infection, but mucus color alone does not tell you whether the cause is viral or bacterial.

Yellow or green mucus can happen with viral infections too, which do not respond to antibiotics. The color comes from immune cells and related enzymes in the mucus as your body fights off the illness.

When to be more concerned

Consider checking with a healthcare provider if you have:

• Symptoms lasting more than about 10 to 14 days without improvement
• A high fever or fever that returns after improving
• Severe sinus pain, facial swelling, or a bad headache
• Trouble breathing, wheezing, or shortness of breath

If the yellow mucus is mild and you otherwise feel okay, it often gets better on its own.