Phlegm might seem like an everyday nuisance, but it can serve as a critical indicator of your body’s respiratory and systemic ...

This cold and flu season, you may be looking for clues you're getting better anywhere you can find them, even in the color of ...

"Its color comes from white blood cells and other waste material." Typically this is linked to colds or sinusitis-an inflammation of tissues in your nasal passages, he adds. Like yellow mucus ...

When a white blood cell finds a germ, it latches onto it. Then it changes its shape to surround the germ. You can imagine the ...

This type of infection can cause bleeding in the airways, and this blood makes the mucus and phlegm appear dark or black. According to the American Cancer Society, there were about 234,580 new ...