Unfortunately there isn't much information out there about what causes flare-ups and what makes them relent. Some people have identified some of their triggers like smells and the like, but most people with chronic illness, including myself, just have to hope that a flare-up doesn't happen when we least can afford it! I know that isn't the answer you were looking for and I wish I had a better answer to give, but that is, unfortunately, a hallmark of COPD and other chronic illnesses - the unpredictability of it all. It is one of the most difficult things to deal with, as you can see: https://copd.net/living/invisible-symptoms All I can say is that at least we are in it together! You can always come here to vent on the bad days and chat on the good days - or vice versa! Keep on keepin' on, DPM