i too have coughed up little specks of red in my phlegm. i have also coughed up black stuff (likely pot tar) and i do not smoke cigarettes. I have told my family,..if i ever die of lung cancer to let it be known,..that marijuan amay actually cause this,..but thats IF i were t get lung cancer. i believe the blood in phlegm could be from various things. inflamed throat,.during cold or dry season alergies take effect in these areas. When blood vessels get dry,they bust,releasing small amounts of blood. the blood could come from in your mouth,on your tongue or even be something red you ate. who knows. all i know is, i feel fine and if i die smoking pot,..so be it. but cigarettes,..quit now. seems harmless (like pot) but the conclusions drawn from cigarette smoking are very real bro, very real.