I get a long sometimes painful cough randomly through out the day and night. I don't have any flu like symptoms orr anything like that. What could cause this? I cough up white flem, sometimes a little darker like light brown. I am a smoker. About a pack a day. I'm 26 years old, live in tucson,az. My email is {removed for privacy} if u need any further info. Thank you for your time.

Well, smoking could cause this, as could a number of different illnesses. Only a doctor can diagnose and treat you properly.

It sounds like something you really need to see the doctor about, no this is not normal by any means