A flare can include any and all of the following: increased cough, mucus production, change in color of mucus, headache, runny nose, sneezing, temperature, fatigue, chilling, and probably a bunch of other things I forgot. My tell-tale for a flare is a change in the color of mucus (that's why it's first on my list!). You may simply have to pay attention to changes (even really small ones) in he way you feel, and to things that may seem not to have much relation to COPD. Way back when I was in really good shape and exercised for 45 minutes before work every day, I knew that if my blood sugar was off by 15 or more points and I had to struggle more on the treadmill than normal, I was having a flare.