Hi Andrew,
I am having a flare right now. Started a month ago and I can tell you, I have no trouble telling when I have a flare. It starts a few days before with major fatigue and wanting to sleep all the time. Then one or two joints will start to throb and within an hour or two, there is swelling, redness and throbbing, indescribable burning agony.
Today it is my right knee and also the Cricoarytenoid joint in my throat. Can barely walk,can't swallow and can hardly talk. Waiting for the Dr's surgery to open so that I can get an appt. today. That is how a flare is for me.