this past summer in the morning when I cleared my throat 2x I had very tiny streaks of blood..I couldn't tell if it was coming from my sinuses(have this problems sometimes) or my lungs because I kind of coughed and cleared my throat at the same time..I went to my doctor who ordered a chest xray and saw a pulmonary doctor who wasn't concerned..I asked my doctor for a cat scan also both were clear..the last time it happened (3rd time)was in August after I ate Ihad mucus coughed and again a little blood streak..I also had a endoscopy thinking maybe it was my throat from reflux..my question is it hasn't happened again but I am 29 and didi smoke for 8 yrs..I quit for good 3 years ago..should I ahve another followu-p test? x-ray again?

If the pulmonary doctor wasn't too concerned chances are it wasn't anything terribly serious. Most serious things that cause blood streaking in the mucus are seen on a chest x-ray (like cancer) so you don't really have to worry about this. It's likely that you cough very hard and rupture a capillary, and this capillary bleeds a tiny amount.

However, if you start noticing a worsening respiratory problem, or more blood in your mucus, or frank blood in your mucus (as in not just teeny streaks or a taste, rather something the size of a clot,) you should definetely see a doctor.

I don't think it'd be a bad idea to keep an eye on it -- mention it to your doctor how often it happens and whatabouts it looks like, like if it only happens when you cough really hard or if you've been exercising very hard or if you're having sinus problems or a bad cold. You *should* ideally be going for a yearly physical. If it isn't causing you any problems and a few chest x-rays (like say 1 a year) show absolutely nothing to be concerned about, I'd not worry about it at all. Some people just have capillaries that are more prone to rupture when they cough forcefully.