What is the cause and effect of spitting up of a brown or black mucus? i've been spitting up a dark brown to almost a black mucus. i do smoke. i am trying to quit.

Oh, : Oh, i answered earlier but i didn't have this info. Smoking can cause mucus black tinged mucus. There is mucus through out our respiratory system. It grabs on to germs, dust, chemicals and things like particles we inspire from tobacco. The mucus than gets pushed along out of our system. I hope that this is a motivation for you to quit. If this continues, recommend that you see your doctor for a thorough evaluation.

Its from smoking: The "tars" - all the hydrocarbons and organic crud in cigarette smoke ( you know the stuff that turns the filter and your fingers dark yellow and brown) is trying to get out. You need to quit. As the famous philosopher yoda from star wars said - there is no try, there is just "do". See your doctor for evaluation, you may have COPD and need treatment, and see if there is lung infection/bronchitis.

Smokers : Smokers tend to caugh up brown mucus which will change to ligher color when you quit untill it disappear. Please keep in mind that could be bloody mucus that need further evaluation. In the other hand the source could be the stomach and will need further evaluation too. Please visit your primary physician.