I am a former smoker, I quit before 7 months, and when I go through bad times too much stress i feel like I am too much sick it's happened to me twice first after quiting 2 month and before 3 days when I had problem me after that i was coughing too much while I was stressed after two days I was feeling too much sick and tired i just slept too long time. Also i feel pain in small area in my lung sometimes i feel it is sometimes i don't. I did test for hemoglobin before 3 months and I am fine.