Quote Originally Posted by jessem98
Me and my buddy are pretty much daily smokers. Now i smoke around the same amount as he does. Over the past year or so he has developed phlegm in which he coughs out, and it contains like black or grey little pieces in it... He has asthma, and his dad smokes like a chimney (in the basement away from everyone). He stopped smoking all together, and started vaping...

Is this from holding in hits? Is it from exposure to cigs?

... Does anyone else have or heard or this?

What could that black/grey material be?
The same stuff that you see going out the non-mouth end of whatever you're burning is the most likely culprit. Ash. Bits of carbon or partially burned weed or tobacco. Smoke particulate. What you're breathing in is what you're coughing out, usually the most recent thing you've smoked or inhaled. You expectorate dust, pollen and pet dander, too, generally. It's caught in the throat, trachea, bronchial tubes and bronchioles and comes out in phlegm/mucus when you cough it up, at least some of it does.

If you work around sand, rocks, or asbestos, that's a little different. Those particles are unique. They lodge in the little air sacs and passages in lungs more easily and can't really be expectorated from those spaces. Once those particles are lodged, the body has an inflammatory defense response and goes through a process that ends with the laying down of collagen over the sand or asbestos particles. That, in turn, ultimately results in fibrotic nodular lesions. Over time, bad news, bad breathing interference.

You don't have fibrotic lung disease or silicosis/asbestosis. You have a too loosely rolled joint or cigarette and are probably inhaling more deeply than you need to and taking in ash, bits of carbon or partially burned weed or tobacco, smoke particulate. It's not uncommon for people to cough up bits of blood, too, which can look red or dark browninsh, if their lungs are very irritated.