What Does It Mean When I Have Yellow Snot with Blood?

Nasal mucus usually suggests that your body is dealing with an infection or allergies. The mucus color is caused by white blood cells, which help fight off threats to the body like viruses, bacteria, and allergens. Sometimes, these white blood cells give the mucus a yellow or green color. The presence of a small amount of blood can happen when the delicate blood vessels in your nose break, often from actions such as blowing your nose too hard or due to inflammation of the nasal passages from the infection or allergies. If the bleeding is light and happens only occasionally, it is usually not dangerous. However, if the blood increases or does not stop, it's important to see a doctor.