I think I caused it by riding in the car for 6 hours while working on my laptop. Then in the middle of the night I woke in terrible pain and had to stay home in bed yesterday. My office mate thought I was playing hooky and when I told him, no, unfortunately, I was not, he felt bad for thinking that. The trouble is that when there is a flare, you fall behind and then end up working harder to catch up and that can cause more trouble. You have to be careful, for sure.
Sue