@cholash I don’t really have any guidance for you other than to say your question is a good one. Both my NTM experts, NJH and UCSF, state in their notes that I am not an exacerbator (not yet anyway) but I had/have (still treating) an advanced NTM infection. So my NTM infection itself was not considered an exacerbation. Why? In my case it might be explained by the fact that at least one of my experts thinks my NTM came first, Bronchiectasis (BE) second. ”Exacerbation” suggests a worsening of something already existing. But certainly we hear all the time that BE makes one more susceptible to NTM and I know many non-expert doctors treating in this area assume the BE preceded the NTM. So, for those with existing BE, why wouldn’t an NTM infection itself be considered an exacerbation? Certainty NTM can do considerable damage, like “exacerbations”, as is true in my case. I agree with Linda that clinicians at times comment that those with BE and NTM often don’t exacerbate as frequently as BE patients without NTM. I believe this comes from a 5 year study published about a year ago that essentially says as much. Most of the BE/NTM heavy hitters in US were involved in that study. But again, why is someone with BE that develops an NTM infection not considered to be having an “exacerbation”. Certainly those with an NTM infection can and do have increased cough, sputum production, sputum changes, etc., all the “signs” of an exacerbation … so what is the distinction? Is it intensity? Does NTM “flare”? That’s an interesting question. Certainly for many it seems more of a slow march but not always. Some are very symptomatic at the time of diagnosis. Maybe they were for a long time, but often symptoms worsen which forces further inquisition with new doctors, etc. Why is this not considered a “flare”. I have seen comments like “acute on chronic infection” on my CT. That sounds like a “flare” to me. So all to say, like you, I don’t understand the distinction. We patients could use a presentation focused solely on exacerbations with a looooooong Q&A session. Lastly, I agree with others the most important thing is to get to the bottom of what is presently going on. Hopefully by now you have taken a respiratory culture (and fungal) to see if anything other than NTM is brewing. It’s possible that your NTM is worsening but seems equally plausible that you just have a cold or something viral that is kicking things up. We all need to keep our medical teams on a short leash (I know, easier said than done) so we respond to these changes quickly and thoroughly. Good luck!