Pollutants, infections, and lung cancer may cause black mucus ... or smoke — for a short period will notice that their mucus returns to a regular color once exposure to the pollutants stops.

You should see a doctor promptly if your cough is accompanied by fevers, chills, night sweats, coughing up blood, shortness ...

According to doctors, seven different mucus colors can indicate various health ... pneumonia or even lung cancer. It's best to schedule a visit with your doctor if you notice blood in your mucus ...

Serious conditions that may cause you to cough blood are lung cancer ... blood-stained phlegm that is thick and dry in consistency. This phlegm may be yellow, green, or brown in color.