Yellow or Green Mucus
Mucus works as a protective layer for your sinuses and lungs. It would keep these parts always moist and prevent them from getting dry. In addition, this sticky substance can filter and trap unwanted components in the air such as dust or bacteria. However, when you are allergic or suffer from an infection that causes a sinus headache, the body will produce more mucus than usual. The main goal is to get rid of bacteria and viruses. While usual mucus tends to be clear or have light yellow, people with sinus headaches will have boldly yellow or green mucus. [5]
