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Lung diseases

Phlegm with black/grey strands



I quit smoking two years ago, but still cough up phlegm and have to expel mucus in my throat/mouth many times a day. Last night and again this morning, the phlegm was either completely dark grey/black or had strands of dark grey/black in it, a few times, it was hardened.

I have allergies, which is what my GP attributes my constant mucus to. What could be causing the dark particles in it now? Could it just be pollution (I spent several hours on the highway yesterday)? It happens when I exercise outside sometimes, too.

Thank you!


The process of coughing up black sputum is called melanoptysis. This is most common in smokers where dark pigments from the inhaled tobacco smoke/residue deposit in the cells of the airways but it can be seen in other conditions such as inhalational drug abuse (smoking crack cocaine), chronic lung diseases associated with occupational exposures such as coal workers' pneumoconiosis ("black lung"), smoke inhalation after a fire, or in cancer of the airways to name a few. It is possible that exposure to airway pollutants could cause it, but the amount of exposure would need to be very heavy (and likely more than you received from sitting in traffic for a few hours.) Chronic allergies and sinusitis can certainly cause chronic cough with mucous production, but would not be likely to cause the melanoptysis. I would encourage you to discuss this further with your physician.

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Response by:

Jennifer  McCallister, MD Jennifer McCallister, MD
Clinical Assistant Professor of Pulmonary, Allergy, Critical Care & Sleep
College of Medicine
The Ohio State University