Ive been a smoker since last September, however this June I reduced drastically from 5-6 a day to only about 6-7 a week. However, I have continued to smoke pot quite frequently, and I am also a singer. Ten days ago, I overstrained my voice while singing for a few hours, and then smoked more than my usual habit for the next few days. It is then that I first discovered droplets of blood in my phlegm. I was completely off both pot and cigarettes for four days, and then after that I've only smoked pot a couple of times, and one cigarette. But again, there was blood in my phlegm. I hardly have a cough, and I DO have a sore throat which prevents me from singing, but nothing too serious/painful. Why is this repeated blood in my phlegm?Is it serious?