I have had numerous episodes of coughing up blood through the years. The first time was totally out of the blue and I choking and gagging on coughing up so much blood. I wouldn't be diagnosed with BE for about 7 years. It didn't happen again for a couple of years. I have since had 2 other extreme episodes and multiple minor ones. They always stop on their own and everytime it happens is frightening. I have pretty much pinpointed the causes as poor air quality or a cold. More extreme episodes air quality. I had a bronchoscopy 3 years ago and they couldn't find a cause and told me my lungs are very friable. They did find that I had MAI. I have multiple air filters in the house and recently bought one for the car. I wear an AirPro when I go outside this summer as our quality can be a problem even in the 20's.
I don't think you ever get use to it and each time is upsetting. I just started taking the NAC and now feel a little concerned from hearing that it can cause bleeding. Haven't take Ibuprofen in years for this reason.