Why does snot turn yellow?

The change in mucus color from clear to yellow is often a sign that your body is fighting off an infection. When you have a viral or bacterial infection, such as the common cold or flu, your body sends white blood cells to the affected area to fight off the infection. These white blood cells produce chemicals that can give mucus a yellow or green color.

In addition, the mucus itself may also become thicker and stickier when you are sick, which can make it appear yellow or green. This is because the increased viscosity of the mucus helps to trap bacteria and viruses, preventing them from spreading further into your body.

In most cases, yellow snot is not a cause for concern and will clear up on its own as your body fights off the infection. However, if you experience any other symptoms of illness, such as a fever, headache, or body aches, it is important to see a doctor to rule out any other underlying medical conditions.